Tomos Throttle Upgrade

August 13, 2008

Tomos 1991-2007 Throttle Upgrade

This is about how to repair an A35 throttle that has a bad “throttle valve”, in case the original part is not available.

Above, the bottom view of the throttle used on all A35 (except A35 Revival) and A55 models from 1992 to early 2008. Everything is black except the light grey “throttle valve”, also known as “sliding block”. It is Tomos part number 223707. Since mid 2008 the controls are different. They say TBS, and the throttle is a wrap-around type, so it has no sliding block.

Above, the same throttle with a pinch bolt upgrade. When the sliding block breaks or strips and cannot hold onto the cable wire, a throttle pinch bolt, 5mm diameter by 7mm long is installed on a new throttle wire just behind the broken sliding block. First a new throttle wire is installed and lubed. The old sliding block must be in otherwise good condition, other than it cannot hold onto the wire. A 5mm diameter by 7mm long throttle pinch bolt is slid over the end of the new throttle wire, and positioned against the sliding block. The wire is pulled taut. The screw is tightened with a small sharp proper fitting screwdriver, very tight. With the engine not running, the throttle is operated to see if it works and feels right. Then the excess wire is cut off, with a sharp wire cutters (diagonals), when the throttle is held at max, engine off. The short tail should be about 1/4″, like shown above. Bend the tail if it hits the grip at max position.

Above left, exploded view. Middle, broken 223707 with pinch bolt back up. Right, pinch bolt 5mm diameter x 7mm.

Warning. Improper installation or using a bigger or different pinch bolt might make the throttle stick or stay on. Many other things can also make the throttle stick, such as lack of lubrication, or a kinked or frayed cable. See Service/Carburetor for info about sticking throttles. Do not let anyone operate the moped if the throttle is sticking. It should always snap back to idle when you let go. This information is for service personnel and competent home mechanics, not just anyone. Please get help if you need it. Use discretion, and use this info at your own risk. The author assumes no responsibility for the use of this information.

Tomos A55 Transmission Oil Leak

August 12, 2008

Occasionally new mopeds, 2008 and later, leak transmission oil (ATF) at the front chain sprocket. The chain then slings the oil onto the rear of the bike. Here’s why.

With the distance bush removed you can see the thin o-ring #31 (033007). The white surface around it is the inner race of the big ball bearing #22. Click to enlarge images.

 

 

Sealing the coaxial drive is tricky. Oil can leak from three concentric circles.

  • 1. the circle between the central pedal shaft and the drive shaft #23
  • 2. the circle between the drive shaft #23 and the distance bush #20
  • 3. the circle between the distance bush #20 and the outer big seal #21.

1. Leaks from inside the drive shaft

Pressed deep into the center of the coaxial driveshaft #23 (223453) is needle bearing #24 (033502). It’s left end has a thin rubber seal. This generally does not leak except in some high mileage machines, or if it is damaged during installation of the pedal shaft by a sharp corner at the end of the pedal shaft, such as caused by crashing or abuse. Tomos intentionally rounds the left end of the kick starter/pedal shaft, so it can’t cut the seal as goes in. When this “inner” seal leaks, the whole engine must be completely disassembled, to replace the driveshaft #23 (223453 for pedal, 223456 for kick), complete, at a cost of about $150 parts and $250 labor. Total $400. This is Option 1A, the way Tomos says in the 1985 A3 Service Manual, “In case of damage to the needle bearings in the main shaft, we suggest it’s replacement with a new complete main shaft.”

Alternatively, the motor can remain installed and assembled, except for the transmission gears and shafts, which are removed from the right side. Then it is possible to remove the leaking left needle bearing from the drive shaft on the right side. A very special custom modified inner jaw slide hammer type bearing puller tool is necessary. Then the cost, in most small shops, is about $220 for making the tool, plus $150 labor, plus $30 parts. Total $400. This is Option 1B, for skilled toolmakers. It is not in any Tomos service manual. But Tomos does sell the parts to do it. 

Left, Tomos says in the 1992 A35 Service Manual, in case of damage to the inner main (drive) shaft seal or needle bearings, to remove them using a suitable tool, and install new ones with press tool 732.367. 

Right, the installer 732.367 with a 16mm to 20mm step. The extractor 706.485 and extractor bridge 706.472 are for extracting the 12mm ID left counter shaft bearing, and the 12mm wheel bearings. Apparently, Tomos does not say how to extract the 8mm and 10mm ID transmission cover bearings, and the 16mm ID drive shaft needle bearings, in any of their manuals.

Much skill and craftsmanship is required to select, make or reshape the tool. Otherwise it tears up the delicate needle bearing, leaving the thin shell stuck in the bottom of a deep hole. That mess takes hours to clean up. The bearings are painstakingly peeled off in small pieces, like peeling a stubborn steel orange that’s down in a tight hole. You can barely reach it and see it. But you save $100.

Left, a Tomos drive shaft 223453 showing the two needle bearings installed. The kick driveshaft 223456 is identical except it is smooth and flat where the ring of ramps is. This particular one has broken all of it’s ramps off. The deepest bearing 033502 has a rubber seal at the left (deepest) end. Above it is 033503, another needle bearing, not as wide and without any rubber seal.

Right, the puller in action. Below right, the bearings are out, but still on the puller.

 

 

Left, the two jaws must fit the 2o.5mm OD yet pass through the 16mm ID.  Wider jaw lips and more jaws would be better.

 

Left, the left sides of needle bearings 033502 and 033503. Right, the right sides.

 

033502 says “SNL  SCE109RS” and 033503 says “SNL  SCE108”. You can see the damage the puller did. You can see the black rubber seal on 033502, near the puller damage. When oil leaks from the center of the hollow coaxial drive shaft, rather than from under the surrounding distance tube 209077, it is from this seal, deep deep inside.

Right, the empty drive shaft with it’s bearings out, plus a thick rubber o-ring #30 (033006). The o-ring is an upgrade that comes on the newest bikes, 2012 and 2013. It is a heavy duty back up to the little seal in the left needle bearing. Left to right, the o-ring goes in the hole first, then the bearing 033502, seal side down, then the bearing 033503. These things are super easy to put in, just press straight in, with precise hammer taps. But they are super difficult to get out, even for professional mechanics.

 These two ways of fixing the inner leak, Option 1A and 1B, are very difficult and/or very costly. They are the options that use Tomos original parts.  

  

 

A better way is with a special sprocket nut, custom made. MM made and sold these from 2003 to 2010, but no more.

At left, the upgrade nut, uses a 32mm wrench, precision machined to accept an off-the-shelf 16 x 24 x 6 metric oil seal. At right, an original Tomos front sprocket nut, M22 x 1.0, uses a 30mm wrench. This is only for when the back side of the sprocket is bone dry, and the pedal shaft is dripping wet where it exits the drive shaft, which means the leak is from circle 1, inside the drive shaft only.

 

 

2. Leaks from outside of the drive shaft

Before 2008: metal to metal in three places

2A. The back side of #20 distance bush 209277 against the front side of the #22 bearing.

2B. The front side of #20 distance bush 209277 against the back side of sprocket #17.

2C. The front side of sprocket #17 against the nut #19 and washer #18.

After 2007: o-ring upgrade, no more metal to metal

2. The beveled surface of distance bush 209077, against o-ring 033007, against #22 bearing.

Before 2008, a scratch on any one of those metal surfaces would cause a leak. But that almost never happened. The parts were always made precise and smooth. What’s funny is that the oil seal #21 rarely or never leaks. Until ’07, only a loose sprocket nut caused a leak. The sprocket and distance bush were almays made flat and never leaked. In 2007 we started seeing wavey sprockets. Dished sprockets on Revival, Streetmate, Arrow had their washer tab hole too far in towards the center. Myrons used to weld part of that and grind flat. Flat 26T sprockets 209078 were made warped by the stamping. Also in 2008 many distance bushs had deep gouges in them.

Tomos upgraded the 209077 distance bush by wedging an o-ring in the corner of driveshaft #23, bearing #22, and the back side of #20, and cut a bevel (about 30 degree angle) cut on the inside back corner of #20, to compress the O-ring as the sprocket nut is tightened. Then the wavey sprockets didn’t matter, since the O-ring stops the oil from reaching the sprocket in the first place. Even though they had the right idea, there were several problems with the 2008-2009 O-ring-sealed distance bushes 209277. Some were installed beveled side out instead of in. Some were made without enough bevel, also cutting the O-ring #033007. The dark colored distance bushes, made in India, in the current (2009) parts inventory are made right. Their bevel is 2.6mm wide. At least some of the ones coming on the 2009-later bikes are made with only a 2.0mm wide bevel, which somtimes pinches the o-ring during installation.

At left is an actual distance bush. It’s made of tool steel. It’s from the current (Aug 2012) Tomos USA inventory. It’s well made and correct. OD=34.75 ID=30.40 H=10.92mm

 

 

 

Right, 3 distance bushes, L to R, cut too much – won’t squeeze o-ring, cut just right, cut not enough – can pinch o-ring.

 

Even with a new o-ring and distance bush, oil still can leak here. Once the o-ring is seated and everything is clean, a liquid gasket such as Three Bond can be applied to the inside of the distance bush. Then the distance bush is put in place carefully, trying to squeeze but not pinch the o-ring. More liquid gasket can be applied to the back of the sprocket. Then the sprocket is put in place. Some more liquid gasket can be applied to the center splines and and front side of the sprocket. Then the tab washer and 22×1 nut is installed and tightened, with liquid gasket on the threads. That tends to be the final answer. 

 3. Leaks from outside of the distance bush

 3. The inner lip of #21 (036620) oil seal, against the rotating outer surface of #20 distance bush 209277. This almost never leaks. The big seal, 036630, size 35 x 47 x 7mm, that you can see, seems to be the obvious guess. That guess is, 9 times out of 10, wrong. Replacing the big outer seal usually does not stop the oil leak (unless the seal was attacked by a screwdriver).

 

Horizontal Cross Section View of Driveshaft Assembly

Colors:  Pink = Transmission Fluid     Green = aluminum case         Note: the upgrade o-ring #30 is not shown

Tomos Balanced Clutch Drum

August 12, 2008

The Tomos two-speed automatic dual clutch drum, located behind the bulge in the right side of the transmission cover, is about 4 inches in diameter and made of two stamped sheet steel drums crimped onto a center tool steel precision shaft with gear. In the picture below, the view is of the outboard side, which is the first speed centrifugal clutch side. Flip it over and you would see an identical drum, facing opposite, with a small 1 inch straight-cut gear, the “first speed driving gear”, attached to the inboard side of the dual clutch drum, which is the second speed centrifugal clutch drum.

These drums can be made slightly out of round. They are machined on the inner surface only, where the clutch shoes slip and grab, according to speed. That machining is always perfect, as the inside surface is perfectly concentric with the one-way needle bearing. The proof is there is never any rapid pulsation during clutch slip. So the drum and clutches function perfectly. When the outer surfaces are out of round, the whole bike vibrates or buzzes, and gets worse when the engine is revved up going fast. That buzzing can be felt most in the hands and feet. It can make the mirrors blurry. It can make the speedometer go wild. It can make things on the bike crack, break off, or come loose.

When the drum is a little off balance, and the set of three clutch shoes is also a little off balance, then the vibration felt in the bike can become worse at times, more or less at random. This is because every time the bike slows down, the centrifugal clutches let go of the drum as the spring pulls them inward, and they begin to rotate inside the drum. Then when the bike speeds back up the clutches fly out and grab the drum, because of centrifugal force. But they end up in a new random location in the drum. If the heavy side of the clutch is opposite the heavy side of the drum, then there will be minimum vibration. If both heavy sides are together, there will be the most imbalance and the maximum vibration felt.

Other things can cause excessive engine vibration. Installing a heavier or bigger piston, like a 65cc, is the most common. Running with a loose flywheel or clutch nut is one. The magneto flywheels all seem to be balanced good, although they have not been tested. Using mis-matched clutch shoes is another. Not only should they all weigh the same, but they should all be equal in wear, not one new and two worn out, for example.

Above, the Tomos clutch drum. This one is extremely out of round, so bad you can see it with your eyes. Look at the thick wall on the left. Now compare that with the thin wall on the right side. Clearly the left side is heavier! When they’re bad they’re usually less than half this much. The out of balance clutches began around 2008. Before that, from 1976 to 2007 there was never any noticeable balancing or vibration problem. The A35 (1991-2006) and A55 (2002-later) have the same clutch drum. The A3 (1976-1990) one looks the same but parts of it are smaller or thinner.

Pressed into the center of the clutch drum is a precision roller clutch, a needle bearing that only turns one way. In the picture below, the roller clutch is installed correctly, with the plain side facing out, and the writing side facing inward. When you rotate an installed Tomos clutch drum clockwise, it engages the crankshaft. When you rotate it counter-clockwise, it spins free. When a Tomos engine seizes or hydraulics (that’s when the piston slams into incompressible liquid – gas or oil), the roller clutch can become damaged. It usually becomes tight or frozen. When a Tomos roller clutch is frozen, the bike will run fine but won’t go into neutral when you slow down to stop.

How to “balance” the drum:

A machine shop or a home machinist with a lathe, can perform a precision cutting operation. The drum is held by it’s inner surface, and turned in a lathe. The high parts of the outer surface are “skimmed off”. Try to leave the lowest part uncut, to give it the most strength.

 

Tomos Stripped Driveshaft

August 12, 2008

On pedal models only, not kick models, during the years 2008-2009, occasionally a driveshaft 223453 would become stripped at the ring of ramps needed for forward pedalling. This can never happen on kick models, because they do not have a ring of ramps. When the ring of ramps becomes stripped, the bike runs fine and kick starts backward fine, but the pedals just spin free going forward and do not propel the bike forward at all.

Left is a 223453 driveshaft brand new. Right is a 223453 stripped at the ring of ramps. No ped, only mo!

Some people live with it like that because it’s expensive to repair. The cast iron chips need to be flushed out, or else one chip can damage any one or even all of the gears. It’s too big a gamble to leave them laying in the bottom back corners of the transmission compartment. If the bike is ever leaned way over, the little iron chunks and bottom oil sludge will be poured over the gears.

More to follow…

 

Tomos A55 Derestriction

August 11, 2008

1. Removing intake air flow restrictor

This is the 2010-later carb, with red silicone over idle mixture screw. The PHVA14 has an idle speed screw, with a big knob sticking out for the rider to use occasionally, and a idle mixture screw, recessed with a slot head, for the service technician to use.

The “elephant trunk” restrictor is exposed, a hidden part of the junction sleeve 233748 that joins the air filter/silencer to the carburetor.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This is after the rough cut.

This is after smoothing and rounding with a rotary file.

 

 

 

 

 

 

 

 

 

 

 

 

2. Replacing the rear sprocket

Sprint, ST and LX models come with 28 tooth. Replace that with 22 tooth and subtract 3 chain links.

Revival and Streetmate models come with 31 tooth. Replace that with 24 tooth and subtract 4 links.

 

 

 

3. Shortening the stock exhaust

Only welders and metal workers can do this. But the benefits are huge. Speed increase from 37 to 43 mph.

 

 

 

 

 

 

 

 

 

 

 

 

Encarwi Service

May 4, 2008

Encarwi Carb Service for Tomos A3 1974-83

This very simple, early Tomos carb is designed to be serviced without removal. After 1985, Tomos A3 & A35 models came with Dellorto SHA14/12 carburetors. The Tomos A3 carburetor is in a confined area above the engine and below the sheet metal gas tank/frame. It is difficult to remove.

 Two super usfeul and easy checks:

1) Check the jet. With a large flat head screwdriver or a 9mm wrench, remove the jet holder #2. Remove the jet #2 with a medium-thin flat head screwdriver. Hold the jet up to a light source, such as a sunny white wall. Look through the tiny hole to see if light gets through. If it’s pitch black it’s completely blocked. If it’s not circular then it’s partially blocked, like by a fiber.

2) Check everything else. When the jet holder is removed, and the gas valve is turned on, gasoline should flow out of the gas tank, through the banjo bolt #16 at the float top #12, and then dribble out the hole where the jet holder was. This is a way to quickly test the fuel system, tank, valve, line, filter, and float, all at once.

If gas does not spill out with the jet holder removed, then gas is not getting to the jet. Check if gas comes out of the tank. If gas is getting to the carburetor, but not getting to the jet, then either the inlet banjo #14 or banjo bolt #16 is clogged, or the float top #12 is clogged, or the float #11 is in upside down, or the float is stuck in the up position. Several things can cause this kind of float to stay up and not drop down and let gas come into the float bowl reservoir: being installed upside down (pointy end goes up), rust powder filling up the guide hole at the bottom of the float chamber, the float bulb being pushed too far down the rod, the wrong float, or a dented float chamber wall.

 

Servicing

The jet holder #4 unscrews from the left side. It holds the jet #3, Bing 3.5mm size 46.

To remove an old, hard, shrunken and very stuck on, fuel hose, be careful not to break off the “neck of the banjo”. That means you only pull straight out and rotate, never pull or twist sideways. If that fails, a diagonal pliers aka dikes aka wire cutters, can be used to cut the old fuel line, parallel to the hose, without cutting the banjo underneath. The cut does not need to go all the way through the old fuel hose, but far enough to weaken it.   

To service the float, loosen the clamp screw #20 and rotate the carb so it is tipped to the right. Remove the 11mm hex head banjo bolt. Remove the two slot head screws #18. Lift off the float top. Lift out the float with your fingers. It should lift out freely and not feel stuck.

Float versions, left 70’s bulb, right 90’s solid

 

 

 

Things that cause not enough gas:

Rust powder filling up the guide hole at the bottom of the float chamber. Remedy is twisting a correct size drill bit with your fingers, to pull the powder up and out of the hole. With the jet holder removed and the gas valve turned on, gasoline should flow out of the tank, through the float valve, and spill out the jet holder hole. The amount should be enough to fill the float reservoir in a few seconds, which is roughly a spoonful every 4 seconds.

The bulb being pushed too far down the rod. Remedy is to push it back up. See the above photo with measurements.

Dented float chamber wall. Remedy is to grind or sand down the high spot.

Blocked float reservoir air vent. Gasoline cannot come in unless air can get out. Remedy is to find where it is blocked at, and remove the blockage. The vent follows a channel in the back mounting surface. An empty float reservoir should fill up in a few seconds after the gas valve is turned on. To test for a blocked air vent, first empty the reservoir, then turn the gas valve on for 8 seconds and then off. Then remove the jet holder, allowing gas to dribble out, to see how much gasoline there was in the reservoir.

Blocked gas tank air vent. Gasoline cannot leave the gas tank unless air comes in. So there is a pin hole in the gas cap. When the tank is full, and the vent hole is blocked, the bike will seem to run out of gas. To test for a blocked gas cap vent hole, first fill the gas tank, then close the gas valve, then remove the fuel hose. Place a clean container under it (to check for purity and to put the gas back in the tank). Turn on the gas and observe the flow. It will flow normal at first. But in a few seconds, as negative pressure builds up, the flow will slow down and stop, if the vent is blocked. If the flow continues for 20-30 seconds (or indefinitely) then the gas tank is vented.

Things that cause too much gas:

Worn float needle tip. Remedy is to sharpen it. Examine the tip with a magnifier. Spin the float with a drill while pressing the tip gently against a sheet of emery cloth or very fine sandpaper, at the same angle, and move it slowly around to fresh parts of the sandpaper. The needle rod must be straight first. Examine the tip with a magnifier. There should be, everywhere on the cone tip, circular sanding marks, and no more circular “potholes”.

The needle is bent. Remedy is to straighten it. Normally the bend is just above the top of the bulb. It is done with just fingers and eyes. Rotate to see which way it needs to go. Bend a little. Repeat. 

The bulb being pushed too far up the rod. Remedy is to push it back down. See the above photo with measurements.

Worn float seat hole. The float valve seat is part of the float top. It is the tiny hole at the bottom of the small hole. Examine the hole with a magnifier. It should be perfectly circular and free of nicks and scratches. Polish it with a spinning tooth pick, or the stalk of a Q-tip. 

Float bulb has gasoline inside it. If the float too heavy, it won’t have enough buoyancy to stop the gasoline from getting in. Remedy is to evacuate the fuel with compressed air, locate the leak hole, and apply a minimal amount of fuel tank sealant. 

 

Servicing the M56 engine’s H12 or H8 Carburetor:

One problem unique to this carb is warping of the engine side surface. This is caused by over tightening the two mount bolts, and maybe also because the heat block behind it is semi-soft. The back side must seal not just air, for good idling, but also there is a fuel passage that can leak because of a warped carburetor body. The remedy is to grind the back side flat again, without taking too much off. In the body, there is a narrow fuel hole at the bottom of another hole, that is impossible to see directly. That hole must be checked and cleaned with carb spray and compressed air. 

The float is the same as the other carbs. The float top is the same except it has no air vent pin hole. The idea was to not let gas spill out the vent hole. Instead the vent goes to the mounting gasket, where there is a small opening to the atmosphere, higher up.

 

 

 

Bing Carburetor Service

May 3, 2008

Bing VergaserContents:

1. Carb Elbows: Long and Short

2. Exploded View and Parts Names

3. Carburetor Service Info Sheet

4. Float Needles: Rubber tip and Metal tip

4. Floats

6. Fuel Mixture is Controlled by Five Things

 

1. Carb Elbows Long and Short

Sachs Bings can have long or short cable elbows.

Puch Bings can have long or short cable elbows.

 

 

 

 

 

 

 

 

 

 

Sachs Bing Cable Elbows: Left photo above, left is the long carb elbow, used on KTM Foxi, Sparta Buddy, and most Sparta Foxi models. Right, is the short carb elbow used on other Sachs engine models. The Sachs elbows are 7mm, not 6mm threads like Puch ones. The bigger elbow allows the throttle cable small end to pass through the 6mm adjuster. So Sachs double-ended throttle cables do not come with adjusters. The adjuster stays with the elbow. Puch Bings have 6mm elbow threads, and 5mm adjuster threads, too small for the cable end to pass through. So Puch double ended throttle cables have the 5mm adjuster trapped in them.    

Puch Bing Cable Elbows: Right photo above, left is the long carb elbow, used on Maxi models, also with the black choke extension. Right, is the short carb elbow used on Magnum type models. The current aftermarket “Puch” throttle cables are made for the short carb elbow. They idle way fast if used with the long elbow, because the slide is not allowed to go fully down to idle. Myrons sells a long elbow throttle cable, for Puch Maxi, made from a modified “Puch” throttle cable. The wire needs to be about 12mm longer. The long elbow comes on Maxi type sheet metal frame models. The short elbow comes on Magnum type tube frames, such as Sears Free Spirit or JC Penney Pinto. The short elbow is so your foot does not hit it when you get on and off the bike. See the exploded view diagram below. Other Bing moped (under 15mm venturi) carburetors are the Sachs Bing, Kreidler Bing, Solo Bing, Tomos Encarwi, Batavus Encarwi, Trac Encarwi. Much bigger Bing carburetors are also on BMW, KTM, Penton, Sachs, Maico, DKW motorcycles, all made in or near Germany.

 

2. Exploded View and Parts Names

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Carburetor Service Info Sheet

Below, the choke slide and throttle slide must be installed simultaneously. It is difficult. The throttle slide has a slot that must line up with a prong in the carb body. The top of the choke slide slides onto a deep wide notch at the bottom of the choke rod, so moving the choke rod moves the choke slide. It often gets left out or disconnected. When the choke slide is disconnected from the choke rod, the choke will be “on”, blocking off the air supply, whenever the throttle slide is down or closed. Normally when a Puch is given full throttle, the choke slide and rod are lifted all the way up until it clicks. The click is the choke rod clip #24 settling into the clip groove near the middle of the choke rod #23. When the throttle cable is not adjusted tight enough, the choke is not lifted all the way off, and it does not click until you manually reach down and pull up on the choke rod. When the throttle cable is adjusted too tight, the engine races and does not idle slow, even with the idle screw loosened all the way. See also General Carburetor Service and Jetting for how to clean and adjust carbs in general. 

 

White Flakes

These white flakes were the cause of a customer’s Puch not running. By chance a tiny spec broke off and lodged in the main jet.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Bing Float Needles 

All “Bing Puch Carbs” have the slotted float type float needle with a rubber cone tip, except for some of the Sears Free Spirit 1/14/163  and 1/14/164 carbs, which have a Sachs Bing type float needle that does not lock into a slot in the float and has a metal cone tip.

 

5. Floats

The original 1970’s floats were white. They weigh 5.6 grams when new. Modern replacements are black. They also weight 5.6 grams. 

After years of exposure, the original white floats gradually absorb ingredients from the fuel and oil. They turn color, first light gold, then gold, then orange-gold, then light brown. The darker the color the more wight they gain, and the less they float.  Orange-gold used floats weigh 5.8 g, light brown ones weigh 5.9, brown ones weigh 6.0 g.

 

6. What part controls mixture depends on how much throttle opening

Slide Carburetors Diagram

 

 

 

 

Ignition and Magneto Service

April 20, 2008

Welcome to Ignition and Magneto Info for 1970s and 1980s mopeds, USA models with brake lights.

Contents:   1 Magnetos    2 Magneto-Points Ignitions

Contents:   3. Clip-on Condenser   4. Magneto Wires Chart 

Contents:   5. Hot Wiring     

 

1. Magnetos

Moped magnetos have two parts, a rotating flywheel/rotor, and a stationary stator.

They have two functions, producing the source of ignition spark, and generating power for lights.

Most magnetos worldwide have two functions that are independent and unrelated. The lights function independently of the ignition, and the ignition functions independently of the lights.

The fact that the headlight comes on when the engine is turned over does not mean that the spark is good or bad, because head lights (except Angel/Speed Bird and Motobecane) are separate from ignition.

 

 

The best resource for moped electrical is Moped Army Wiki. www.mopedarmy.com/wiki/Electrical

Tomos A3 Stator

Typical Stator Assembly: At left is an original 1974-1986 Tomos A3 stator, the stationary part of the magneto. Left is the points, right is the condenser, top is the ignition source coil (with two output wires, black and blue), bottom is the lighting source coil, with one output wire, yellow, at top right (not the yellow from condenser to points). The ignition source coil has an external ground (the blue wire), while the lighting coil has an internal ground (the solder joint at lower right).

 

 

 

 

 

 

 

 

2. Magneto-Points Ignitions

 

 

 

Below is another Myrons hand-out sheet explaining internal and external ground ignition circuits.

 

3. Clip-on Condenser

How to tell if the condenser is bad:

This is a very useful troubleshooting technique. A condenser can be added temporarily without removing any parts. At left is a “Clip On Condenser” a valuable tool. When a running bike is having ignition misfires due to a bad condenser, this external condenser will reduce or stop the misfiring or “hiccuping”. It can be any older automobile condenser. It can be located anywhere along the wire that runs from the points, inside the magneto, to the spark coil outside the engine. It only takes a few seconds to “T” the condenser off the coil wire, clip the ground somewhere, and go riding.

 

External condenser diagram

 

 

 

 

 

 

 

 

 

4. Magneto Wires Chart

Myrons Magneto Wires: what the wires do and which are needed to run

Myrons Magneto Wires: what each wire does, and which are needed to run

 

The Magneto Wires Chart above is like a master key that unlocks a lot of different mopeds. Knowing the color and function of the magneto wires allows a moped engine to be “hot-wired” to run without any of the bikes wires.

 

5. Hot Wiring

“Hot wiring” is the same as making an engine run, say on a work bench, completely separate and disconnected from the bike. Certain magneto wires matter, and must go to certain places. Other magneto wires are for lights only. The ignition wire must always go from the magneto (points, condenser, and source coil) to the spark coil, and not also to ground. The ignition ground wire must always go from the magneto (source coil ground) to ground. You can make this happen easiest with alligator clips on the ends of wires, like little jumper cables, called clip leads.

 

To make any moped motor run on a work bench, you need some clip leads, a spark coil, a good spark plug, and the knowledge of what each magneto wire does. For example, on most Puchs, blue is ignition, and blue/black is ignition ground. On a Garelli, black is ignition and blue is ignition ground. On a Derbi, green is ignition and blue is ignition ground. Sometimes the wire colors are faded to grey, dark brown, or black. Then slice some skin off with a sharp knife to expose the true color inside.

 

 

6. Extending a Copper Core Spark Plug Wire

 

 

Tomos Wiring Diagrams

April 13, 2008

Welcome to New Tomos Wiring Diagrams, 1992 and later, A35 and A55 engines (not A3 1976-91). 

Tomos 1992-93

Tomos Bullet A35
Bullet TT, 1992-93

Tomos Colibri 1992-96

Tomos Colibri
1992-96

Tomos Sprint 1993-97

Tomos Sprint 1993-97

Tomos Targa 1994-95 Tomos Targa LX 94-95

Tomos Targa 1994-95
Tomos Targa LX 94-95

 

 

 

 

 

 

 

Tomos Targa 1996-97 Tomos Targa LX 96-97

Tomos Targa 1996-97
Tomos Targa LX 96-97

Tomos Sprint 1998-01

Tomos Sprint 1998-01

Tomos Targa 1998-01 Tomos Targa LX 98-01

Tomos Targa 1998-01
Tomos Targa LX 98-01

Tomos Revival 2001-02

Tomos Revival 2001-02

 

 

 

 

 

 

 

Tomos Revival 2002-07

Tomos Revival 2002-07

Tomos Sprint 2002-07

Tomos Sprint 2002-07

Tomos Arrow 2005

Tomos Arrow 2005

Tomos Arrow-R 2006-08

Tomos Arrow-R 2006-08

 

 

 

 

 

 

 

Tomos Streetmate 05-07

Tomos Streetmate 05-07

Tomos Streetmate 08-12 Tomos Str.mate-R 08-13

Tomos Streetmate 08-12
Tomos Str.mate-R 08-13

Tomos Revival 2008-12+

Tomos Revival 2008-12+

Tomos Sprint 2008-13 Tomos ST 2008-2013 Tomos LX 2008-2012

Tomos Sprint 2008-13
Tomos ST 2008-2013
Tomos LX 2008-2012

 

 

 

 

 

 

 

 

California Vehicle Codes

August 12, 2007

Welcome to Myrons Mopeds – Moped Laws – California (each state and country is different).

There has been confusion throughout the state of California ever since 1996 about the moped laws. Most people think you don’t need a license, if it’s under 50cc and has pedals. The confusion comes from the dual definition of motorized bicycle, which came out in 1996. In the 1970’s when mopeds came to the USA, you did not need a license. Ever since about 1981 you have needed a drivers license on a moped. Since 1989 it’s been a motorcycle class license. From 1996 to 2014, 20 mph 1000 watt electric bicycles don’t need a license. Since 2000, motorized scooter laws came out. In 2014, electric bicycle speed and power limits became 28 mph and 750 watt. California has more motorbike and oddball vehicle laws than most states. 

In a nutshell, the California laws for mopeds are the same as motorcycles, except for the motorized bicycle license plate. The requirements are M2 or M1 drivers license or permit, liability insurance, helmet, moped license plate, plus street legal lighting and safety equipment.

 

CVC 406(a) defines a “motorized bicycle”, commonly called a moped, as a two- or three-wheeled device having fully operative pedals for propulsion by human power, or having no pedals if powered solely by electrical energy, and an automatic transmission and a motor that produces less than 4 gross brake horsepower and is capable of propelling the device at a maximum speed of not more than 30 miles per hour on level ground. 
CVC 312.5(a) defines an “electric bicycle” as a device which has fully operative pedals and an electric motor with an output of not more than 750 watts.
 
(1) A “class 1 electric bicycle,” or “low-speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour.(2) A “class 2 electric bicycle,” or “low-speed throttle-assisted electric bicycle,” is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour.(3) A “class 3 electric bicycle,” or “speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer.
24016. (b) A person operating an electric bicycle is not subject to the provisions of this code relating to financial responsibility, driver’ s licenses, registration, and license plate requirements, and an electric bicycle is not a motor vehicle. 
 

California Vehicle Codes – Moped Related

Compiled from the 2016 California Vehicle Code by Shaun Strahm, Myrons Mopeds

Definitions:

312.5(a) Electric bicycle: is a bicycle with operable pedals and an electric motor of less than 750 watts.

(1) A “class 1 electric bicycle,” or “low-speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour.

(2) A “class 2 electric bicycle,” or “low-speed throttle-assisted electric bicycle,” is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour.

(3) A “class 3 electric bicycle,” or “speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer.

313 Electric Personal Assistive Mobility Device (EPAMD): 2 wheels side by side, 12.5mph max (Segway).

400 Motorcycle: any motor vehicle with 2 or 3 wheels, a seat, and weighs under 1500lbs.

405  Motor-Driven Cycle: any motorcycle less than 150cc, but not a motorized bicycle.

406 Motorized Bicycle: 2 or 3 wheels, pedals & gasoline motor, or no pedals & electric, under 4hp, under 30mph.

407 Motorized Tricycle or Quadricycle: 3 or 4 wheels, gasoline motor, under 2hp, under 30mph.

407.5 Motorized Scooter: 2 wheels, handlebars, designed to be stood upon, and is not 313, 400, 405, 406, or HSC108550.

415 Motor Vehicle: any vehicle that is self-propelled. Exceptions: Motorized wheelchairs, motorized tricycles, and motorized quadricycles are not motor vehicles when driven by disabled persons or senior citizens who are unable to walk. A toy, HSC 108550, is also not a motor vehicle.

467(a)  Pedestrian: a person who is afoot or (1) propelled by human power, other than a bicycle, or (2) an electric personal assistive mobility device (EPAMD).

467(b)  Pedestrian also includes a person who has difficulty walking and is operating a motorized wheelchair or motorized tricycle.

Motorized Bicycles (Mopeds) CVC 406:

4020. Motorized bicycles are exempt from registration.

5030 Motorized Bicycles 406 (mopeds) are required to have a special license plate.

The DMV Form 230 Motorized Bicycle Instructions and Application (PDF) is one form for four purposes.
1. for original application (when the moped has never had a CA moped plate)
2. for transfer of ownership (when the moped has or once had a CA moped plate, and is sold)
3. for lost plate or document (when either the license plate is lost or the registration document is lost)
4. for if the vehicle has been destroyed or dismantled

The form says to mail it to the Sacramento main DMV. Most of the local DMV offices cannot process Form 230.
The form does not say the fee amount. It was only $5 in the late 80’s and early 90’s.
Since he 2000’s, sending $20 has always been enough. It usually takes 2-3 weeks, but occasionally 2-3 months.

5031 Application Form contents

5032 5-Day grace period (retail sale)

5033 Can apply by mail

5034 Special dealer license plate

5035 10-Day grace period (transfer)

5036  Service Fee of $5

5037  License plate required after 1981

5038 DMV keeps records of stolen mopeds

5039  Moped dealer not required to be licensed

24015 Mopeds must have headlamp, tail lamp, stop lamp, reflectors, mirror, horn & muffler.

23135  Unlawful to drive a modified moped

24015(c) Equipment required on motor-driven cycles & motorcycles does not apply to mopeds

Drivers License Laws:

12500  Unlawful to drive a motor vehicle, motorcycle, or motorized bicycle unless licensed.

12501  Government employees, farm workers, off-highway vehicles don’t need a license.

12502 A nonresident may operate a motor vehicle with a license from their home jurisdiction.

12503 An adult nonresident whose home state or country does not require a drivers license may operate a motor vehicle owned by him without a license for a period of 30 days.

12509(a) Instruction Permit Requirements: must be over age 15 and either is taking or has completed both driver education and driver training, or must be over age 17 ½.

12509(b)  Instruction Permits are valid for no more than one year (12 months).

12509(c) For cars, must be with a person over 18 with valid license in the front seat.

12509(d) For motorcycles and mopeds, must not carry a passenger or drive at night or on freeways.

12513 Special Junior Permit Drivers License for persons over age 14:

12513(a) Only issued when there is absolutely no other means of transportation to and from school.

12514 The Junior Permit can last until age 18, but is revoked if violations occur.

12804.9  Drivers License Classes: A(big rig), B(bus), C(car), M1(motorcycle), M2(moped)

12804.9(b)(4)  Class M1: 2-wheeled Motorcycles, Motor-driven Cycles, Motorized Bicycles 406

12804.9(b)(5)  Class M2: 2 or 3-wheeled Motorized Bicycles 406

12804.9(g) M1& M2 driving test not required if you complete the motorcycle safety class.

12804.9(h)  Any licensed driver may operate a short-term rental moped without an M2 endorsement.

12804.9(i) Under 21 must complete the motorcycle safety class to get an M1 or M2 license.

12814.6 Special Drivers License for persons under 18: Requirements and Restrictions.

12814.6(a)(3)  Must have had an Instruction Permit for 6 months.

12814.6(a)(4to5)  Must have completed drivers education, drivers training, and 50 hours of practice driving.

12814.6(a)(8)(A)  First 6 months: Must not drive between 12am and 5am or with anyone under 20 years old unless accompanied by a licensed driver over 25.

12814.6(a)(8)(B)  Second 6 months: Must notdrive between 12am and 5am unless with a driver over 25.

12814.6(f) A police officer cannot stop a vehicle only to check for  12814.6(a)(8)(A)or(B) violation.

16020 Financial Responsibility (Insurance) required on all motor vehicles.

Bicycles:

21200 Bicycles driven on public streets are subject to same laws as motor vehicles.

21200.5 Unlawful to drive a bicycle while under the influence of alcohol or drugs.

21201(a)  Bicycles must have a rear brake that can skid the tire on dry pavement.

21201(b)  Bicycle handlebars must be below the level of the operator’s shoulders.

21201(c)  Bicycle size must be small enough to stop with at least one foot on the ground.

21201(d)  Bicycles at night must have headlight, rear reflector, pedal and side reflectors.

21201.5  Unlawful to sell a bicycle without reflectors.

21202  Bicycles must stay on the far right of the road way unless it’s unsafe to to so.

21203  Unlawful to hitch rides on another vehicle..

21204  Unlawful to ride a bicycle in any position other than astride a permanent seat.

21205  Unlawful to carry an object that prevents keeping at least one hand on the handlebar.

Bike Paths and Sidewalks:

21206  Local authorities may regulate the operation of bicycles on sidewalks.

21207  Local authorities may establish bicycle paths that are separate from roadways.

21207.5  Motorized bicycles not allowed on bicycle paths unless local authority permits.

21208  When a bicycle lane is alongside a roadway bicycles must ride in it.

21209  Motor vehicles are not allowed in bicycle lanes.

21210  Unlawful to park a bicycle on the sidewalk in a way that blocks pedestrian traffic.

21211  Unlawful for a pedestrian or a vehicle to block a bicycle path.

21212 Persons under 18 years old must wear a bicycle helmet when operating a bicycle.

Motorized Scooters CVC 407.5:

21220 Intent of the Legislature

21221 Same responsibilities as motor vehicles, accident reporting, obeying officers, parking, etc.

21221.5 Can’t drive under the influence

21223 At night must have headlight and reflectors

21224 Insurance and registration not required

21225 Local authority may require registration

21227 Motor must cease to function when throttle is released

21228 Must stay to the right except to pass or avoid hazards

21228 When making a left turn, must stop, dismount, and cross the road as a pedestrian

21229 Must stay in bicycle lane if the roadway has one

21230 May drive on bike trails, unless local authority prohibits.

21235(a) Can’t drive without brakes

21235(b) Can’t drive on streets above 25mph unless in a bicycle lane

21235(c) Must wear a bicycle helmet, properly fastened.

21235(d) Must have a valid drivers license or permit.

21235(e) Can’t carry passengers

21235(f) Must have at least one hand on handlebar

21235(g) Can’t drive on the sidewalk

21235(h) Can’t have handlebars higher than shoulders

21235(i) Can’t park on the sidewalk

21235(j) Can’t hitch a ride on another vehicle

22411 Can’t drive over 15mph

21663  Unlawful to operate or move a motor vehicle on the sidewalk, except electric carts used by postal workers, electric wheelchairs and motorized tricycles used by disabled and elderly.

Golf Carts, Bike Lanes, Freeways, Roller Skates, Misc:

21100.4  Local authorities may regulate electric carts used by postal workers on the sidewalk.

21114.5  Local authorities may allow electric carts on the sidewalk, when operated by postal workers, disabled persons, or persons over 50 years old.

21716 Golf Carts may be driven on streets with a 25mph or less speed limit.

21960 Local authorities may regulate freeway access to pedestrians, bicycles, and motor-driven cycles

21966  Pedestrians not allowed to walk in bicycle lanes when there is a sidewalk next to it.

21967  Local authorities may regulate the operation of skateboards on streets and sidewalks.

21968  Unlawful to operate a motorized skateboard on any street, bike lane, or sidewalk.

21969  Local authorities may regulate the operation of roller skates on streets and sidewalks.

23130.5  Noise limits: big trucks 82dbA, motorcycles 77dbA, all other motor vehicles 74dbA.

Electric Bicycles CVC 312.5:

24016  Special Requirements & Exemptions for Electric Motorized Bicycles 312.5

24016(a)(1) Must meet same federal safety standards as for bicycles.

24016(a)(2) Motor must cease to operate either when brakes are applied or switch is released.

24016(b) Don’t need drivers license, insurance, or registration. 312.5 is not a motor vehicle.

24016(d) Unlawful to modify a motorized bicycle 312.5 to increase it’s speed.

Motorcycle Equipment:

24951(b)(4)  Turn signals required on motorcycles and motor-driven cycles made after 1973.

25650 Motorcycle headlights, 1 or 2, must be on at night.

25650.5  Motorcycles made after 1978, headlights, 1 or 2, must be on all the time.

25651 Motor-driven cycle headlights

26709  Mirrors required:1 on motorcycles, 2 on cars, must have clear view of what’s behind.

27150 All motor vehicles must have an adequate muffler.

27800 Unlawful to carry a passenger on a motorcycle or motorized bicycle unless it’s equipped with a passenger seat and passenger footrests.

27801(a)  Unlawful to drive a two-wheel motorcycle with a seat height that prevents the driver’s feet from reaching the ground when astride the seat,

27801(b)  or with handlebars higher than the level of the driver’s shoulders.

27802  Motorcycle helmets must meet federal standards and be approved.

27803(a) Drivers and passengers of motorcycles and motorized bicycles must wear helmets.

Other Policies:

Persons who have had their drivers license suspended because of a DUI, or revoked because of poor vision or a medical condition such as epilepsy, are sometimes granted an M2-Only driving permit, to-and-from work or school only. The person must be in otherwise good standing for this exception.

Sometimes mopeds are allowed on certain freeways. Every freeway on-ramp has a sign that says “Pedestrians, Bicycles, Motor-Driven Cycles Prohibited”. But on certain stretches where there are no parallel surface roads, bicyclists have lobbied to have the signs removed, or sometimes just the word “Bicycles” blanked out. Wherever they allow bicycles on, there’s always a sign later that says “Bicycles Must Exit”. Local examples are I5 through Camp Pendleton (bicycles only not mopeds), between San Clemente and Oceanside, I15 through the Cajon Pass, from Cleghorn Rd to Hwy 138, I15 through Rancho Bernardo at Lake Hodges. Through ths Santa Ana River corridor along the 91 Freeway there’s a 2 mile strip of bike path, from Green River Rd to Gypsum Canyon. See Laws/Caltrans Policies for how light motorcycles are unfairly prohibited on these and other corridors. Long distance bicycling guide books are a good source of information. So is CABO, California Accociation of Bicycling Organizations website.

 

« Previous Entries
Next Entries »