Magura Controls

July 14, 2014

updated 2020-05

Contents:  1. 70’s – 80’s Magura Parts
Contents:  2. Magura Moped Controls
Contents:  3. Service Information

 

Magura 1975 logo

 

German flag

 

 

 

 

Magura was founded in 1893 by inventor Gustav Magenwirth as a manufacturer of gasoline motors, hydraulic press pumps and water pressure devices. Since 1923 in Bad Urach, Germany, they have produced handlebars and handlebar controls for mopeds and motorcycles. They are an industry leader, and still produce handlebar controls for all major makes. Since the 1970s, the company has also made many products for the bicycle industry. The name Magura is from Magenwirth and Urach. The logo is from a rotary rack developed in 1930.

Magura levers late and early

Left 80’s, right 70’s

Wrap-around and Slide-type: There are two main types, wrap around where the throttle cable wire wraps around and attaches to the twist tube, and slide type where the throttle cable attaches to a block that slides in a spiral slot in the twist tube.

70’s and 80’s: It is a subtle difference, but side by side you can see there are two different folded aluminum original Magura levers. The 1980’s “late” right lever, on the left, is longer and straighter than the 1970’s “early” left lever, on the right. When they are not side by side, it is really hard to notice. 

 

 


1970’s -80’s Magura Parts

Price colors: dark green is good-used, green is new, N/A is not available
Abbreviations:  TBCH is threaded brake cable hole,  TBLSH is threaded brake light switch hole, AC is auto choke

Right assemblies with item #s and links to photos
R1    N/A    2b 3x 4 6 7 9 10s 13a 15a 70’s silver use R3
R1b  N/A    2b 3x 4 6 7 9 10s 13b 15a 70’s black use R3b
R1n $55.0 2b 0x 0 6 7 9 10s 13n nox 70’s silver, no twist tube, no BLSTH
R2   $85.0 2b 3a 4 6 7 9 10s 13c nox 70’s silver, AC (74-79 Tomos)
R2b  N/A    2b 3a 4 6 7 9 10s 13d nox 70’s black, AC (78-79 Tomos) use R4R
R3   $74.0 2c 0x 4 6 7 9 10s 13e no   80’s silver
R3   $53.0 2c 0x 0 6 7 9 10s 13e no   80’s silver, minus twist tube
R3b $79.0 2c 0x 4 6 7 9 10s 13f15z  80’s black
R3b $52.0 2c 0x 0 6 7 9 10s 13fno   80’s black, minus twist tube
R3r$67.0 2r0x 4 6 7 9 10s 13r  no   all black Agis replica
R4    N/A    2c 3a 4 6 7 9 10s 13g nox 80’s silver, AC (80-85 Tomos) use R4R
R4b  N/A    2c 3a 4 6 7 9 10s 13h nox 80’s black, AC (84-85 Tomos) use R4R
R4r$75.0 2r3a 4 6 7 9 10s 13snox all black Agis replica, AC auto-choke
R5p  N/A    2b 3x 4 6 7 9 10a 13p 15a 70’s silver TBCH (Peugeot)
R5q  N/A    2c 3x 4 6 7 9 10a 13q 15a 80’s silver TBCH (Peugeot)
R6b$55.0 2b 0 4b 6 7 9 10s 13u nox 70’s black open-type wrap-around
R7    $65.0 2c 22-25 6 7 9 10s 21x no  80’s black slide-type (Puch Maxi Luxe)
R7c  N/A    2e 22-25 6 7 9 10s 21x no  80s blk slide-type cast lever (Magnum)

 

Left assemblies with item #s and links to photos
L1   $42.0 1b 6 7 8 10s 12a 14 16 17 18 70’s silver
L1b $45.0 1b 6 7 8 10s 12b 14 16 17 18 70’s black
L2   $38.0 1b 6 7 8 10s 12c 14 00 00 00 70’s silver brake only (74-79 Tomos)
L2b $40.0 1b 6 7 8 10s 12d no 00 00 00 70’s black brake only (78-79 Tomos)
L3   $47.0 1c 6 7 8 10s 12e 14 16 17 18 80’s silver
L3b $40.0 1c 6 7 8 10s 12f 14 16 17 18 80’s black
L4   $39.0 1b 6 7 8 10s 12g 14 00 00 00 80’s silv brake only (80-85 Tomos)
L4b $39.0 1b 6 7 8 10s 12h 14 00 00 00 80’s blk brake only (84-85 Tomos)
L4p $32.0 1p 6 7 8 10s 12g 14 00 00 00 80’s park-brake only (Tomos trike)
L4r$29.0 1r  6 7 8 10s 12r  no 00 00 00 all black Agis replica TBCH only
L5p  N/A    1b 6 7 8 10a 12p 14 16 17 18 70’s silver TBCH (76-79 Peugeot)
L5q  N/A    1c 6 7 8 10a 12q 14 16 17 18 80’s silver TBCH (80-83 Peugeot)
L6    N/A    1c 6 7 8 10s 12fno 16 17 18 80’s black (78-84 Puch Maxi Luxe)
L6e $40.0 1e  6 7 8 10s 12b no 16 17 18 70’s black (78-79 Puch Magnum)
L6c $48.0 1e  6 7 8 10s 12fno 16 17 18 80’s black (80-84 Puch Magnum)
L8   $24.0 no 0 0 0 10s 12z 14 16 17 18 start only (Sachs 505 foot brake)

 

All of these levers interchange and are 12mm wide at the pivot.
Original levers have a 6 mm top hole and a 5 mm bottom hole.
Some bottoms are the same as tops, others have a cable slot.
Flipping (using a right lever on the left side or visa versa):
Right and left interchange when flipped (bottom becomes top).
If the lever is flipped the pivot bolt must also be flipped, unless
the 5 hole is drilled to 6 and the 6/5 pivot bolt changed to 6/6.

1 Left levers:
1a  $38.0 L lever folded alum. no ball
1ar
$12.0 L lever folded steel  generic no ball
1ar $00.0 needs 6/6 pivot bolt to work well

1b  $25.0 L lever folded al. used straight
1bs $20.0 substitute: lever 2b upside down
1bs $00.0 for bolt 6a installed upside down
1bd $28.0 substitute: 2bd upside down + 6e
1bd $00.0 for bolt 6a installed right side up

1c   $29.0 L lever folded alum. long
1cr $24.0 L lever folded alum. generic long
1d   N/A    L lever folded alum. black
1dr  N/A    L lever folded alum. generic black

1e  $36.0 L lever cast aluminum
1er  N/A    L lever cast aluminum TCCD
1g  $25.0 L lever folded aluminum Agis black
1gd $14.0 2g drilled to 6/6 (both holes 6mm)
1gd $00.0 needs 6/6 pivot bolt to work well

1p  $26.0 L lever folded al. with parking brake
1p   $00.0 mostly for three-wheel mopeds

2 Right levers:
2a  $34.0 R lever folded alum. Magura no ball
2ar $12.0 R lever folded steel  generic no ball

2b  $20.0 R lever folded alum. Magura short
2bu $15.0 2b good used or straightened
2bd $22.0 2b drilled to both holes 6 mm
2c   $20.0 R lever folded alum. Magura long
2cr  N/A    R lever folded alum. generic long
2d  $32.0 R lever folded alum. Magura black
2dr  N/A    R lever folded alum. generic black

2e  $25.0 R lever cast aluminum Magura
2er  N/A    R lever cast aluminum TCCD
2g   $12.0 R lever folded aluminum Agis black
2gd $14.0 2g drilled to 6/6 (both holes 6mm)
2gd $00.0 needs 6/6 pivot bolt to work well

S Lever sets R and L: with item #s
Sg   $26.0 lever set black 2gd 1gd 6b 6b 7d 7d
Sgb $30.0 lever set black 2gd 1gd 6c 6c 7c 7c
Sb   $44.0 lever set short  2b  1bd re-use bolts
Sbb $38.0 lever set short  2b   2b  flip left bolt

3 Lower right levers:
3x none  right thumb lever original, locks-in off bar
3a $26.0 choke trigger and spring for early Tomos A3
3b none  right thumb lever replacement, locks-in off bar

 

4 Twist tubes: with grip length
 $32.0 twist tube 100 mm original white (cable loads from front)
4b $27.0 twist tube 100 mm original black (cable loads from front)
4c none
 twist tube 115 mm original black (cable loads from front)
4g
none  twist tube 100 mm #4 with ribbed grip #15 original

4r$25.0 twist tube 100 mm Agis black (cable loads from back)

For best performance, this should fit and be smooth
where the lever rubs at.

The 8b spring goes inside the hollow lever, so it fits either side.

 

 

 

 

 

 

 

5 to 11 Hardware
5    $1.50     friction plate to make throttle stick (leave off)
6a  $4-$2  pivot bolt 6/5 orig slot dome M5 x 20 smooth ∅6  x  8.5
6b  $1.20   pivot bolt 6/6  allen short    M6 x 20 smooth ∅6  x  2.0
6c  $3.00   pivot bolt 6/6  black phillips M5 x 25 smooth ∅6 x 11.5
6d  $6.00   pivot bolt 6/6  6a with 6e    M5 x 20 smooth ∅6 x 11.5
6e  $4.50   adapter sleeve changes 6a to 6d  ∅5 smooth ∅6  x  3.0
6f   $0.70   pivot bolt 6/6  allen head     M6 x 20 not smooth
6g  $0.80   pivot bolt 6/6  phillips head M6 x 20 not smooth
7a  $0.70   pivot nut M5 plastic-lock original light gray
7b  $0.70   pivot nut M5 plastic-lock original black
7c  $0.55   pivot nut M5 metal nylock
7d  $0.90   pivot nut M6 metal nylock
7e  $1.00   pivot nut M5 metal nylock black
8    $6.50   left return spring
8b  $2.00   return spring R or L (not for solid cast levers)
  $2.00   right return spring
10s $2.00   clamp screw M6x16 slot dome head
10a $0.70   clamp screw M6x16 allen head (Peugeot)
11  $4.00   socket bolt  aka cable anchor/adapter

 

12 Left housings: with brake switch hole, unless noted
12a $15.0 left housing 70’s silver
12b $15.0 left housing 70’s black
12c $15.0 left housing 70’s silver no start lever (74-79 Tomos)
12d $17.0 left housing 70’s black no start lever (78-79 Tomos)
12e $22.0 left housing 80’s silver with mirror hole
12f$22.0 left housing 80’s black with mirror hole

12g $15.0 left housing 80’s silver no start lever (80-84 Tomos)
12h $15.0 left housing 80’s black no start lever (84-85 Tomos)
12n $10.0 left housing 70’s silver no brake light switch hole
12p $40.0 left housing 70’s silver with TBCH (76-79 Peugeot)
12q  N/A    left housing 80’s silver with TBCH (80-83 Peugeot)

1974-85 Tomos auto-choke 
Thumb button activates choke by
allowing grip to twist in reverse.

13, 21 Right housings: with brake switch hole, unless noted
13a none  right housing 70’s silver
13c $44.0 right housing used 70’s silver with choke slot (74-79 Tomos)
13e none  right housing 80’s silver
13f$39.0 right housing 80’s black
13g $39.0 right housing used 80’s silver with choke slot (80-85 Tomos)
13h $39.0 right housing used 80’s black with choke slot
13n $35.0 right housing 70’s or 80’s silver no TBLSH (Euro version)
13p $54.0 right housing 70’s silver with TBCH (76-79 Peugeot)
13q $42.0 right housing used 80’s silver with TBCH (80-83 Peugeot)
21   $25.0 right housing black screw-slide-type  (some 78-83 Puch)
21b $34.0 right housing used black slotted-slide-type (some 84-86 Puch)

 

14, 15 Grips:
14   $3.00 left  grip  100 mm black ribbed original
14b $11.0 left  grip  100 mm black waffle used
14c $6.00 left  grip  115 mm black block original
15   $18.0 right grip 100 mm black ribbed original
15b $14.0 right grip 100 mm black waffle used
15c $9.00 right grip 115 mm black block original
20   $12.0 grip set 105 mm #14, 15 ribbed replica
20c $12.0 grip set 115 mm 14c, 15c block original

16 Left lower levers:
16  $14.0 start lever new black plastic with screw
16b $32.0 start lever aluminum long w/screw (Puch 2-spd)
17  $1.50 pinch screw 4mm
18  $3.00 pivot pin
18b $1.00 pivot pin substitute screw M4x20

 

Magura slider: left is worn, right is new

19-25 Other things:
19
 $10.0 clamp-on metal lever substitute for trigger #3
22  $3.00 roll pin for twist tube 2.15 x 26 for 2.0 hole
23  $3.00 screw for sliding block (some 78-83 Puch)
24  $15.0 sliding block screw type (some 78-83 Puch)
24b  N/A    sliding block late no screw (all 84-86 Puch)
25  $28.0 twist tube Puch slide-type plastic

 

 

 

Magura Moped Controls 


Sears Allstate throttle control

Sears Allstate right control

Sears Allstate left control

Sears Allstate left control

Magura “Open Wrap Around” silver controls are used on 1950’s and 1960’s Puch, Tomos, Sears Allstate, and many others. Some are cast aluminum levers, and some are folded sheet aluminum.

Most of these did not have threaded holes for brake light switches.

Ball-end levers began in the 1970’s, for safety.  

 

 


Magura late open wrap around right control

Magura late open wrap around right control

Magura black left

Left black housing,
both start cable and
brake cable holes are
plain with bottoms

Magura “Open Wrap Around” black controls were on 1980’s Euro models, but not on US models.

Like the other Magura wrap around throttle controls, the twist tube has a groove that locks onto a tab in the housing. The two are locked together first, then slid onto the handlebar. Once on the handlebar they cannot become separated.

These have a plain hole with bottom, for the brake cable. Most do not have a hole for the a brake light switch.

 

 

 


Peugeot or Not Peugeot: There are two ways to stop the brake cables. The Peugeot way is to have 6mm threaded bottomless holes in the housings with 6mm adjusters stopping the cables. The non-Peugeot way is to have the housings stop the cables (or the inline Magura-type adjuster) with a slotted recess (hole with a bottom) instead of threads. You can convert to Peugeot style by drilling and tapping to M6-1.0 thread. But there is almost no adjustment range (because most of the hole is already too big, 7mm).

Magura wrap around throttle illustration

Magura right control
(with choke trigger)
plain with bottom
for no adjuster or
Magura type adjuster

Magura wrap around throttle threaded brake hole

Magura right control
(with choke trigger)
threaded M6-1.0 for
brake cable adjuster

Magura left housing versions

Brake cable hole versions:
L, threaded bottomless hole (Peugeot)
R, plain hole with bottom (non-Peugeot)

 

 

 

 

 

 

 

 

 

 

 


Magura wrap around silver housing

Magura right housing
with brake switch hole,
brake cable hole is plain with bottom

Magura left control Tomos 213706

Magura left control for
Tomos (no start lever),
no brake switch hole,
brake cable hole is
plain with bottom

Magura “Wrap Around” silver controls are used on 1970’s Batavus, Colombia, Flandria, Foxi, Flying Dutchman, Hercules, JC Penney, Kreidler, KTM, Kynast, Murray, Odyssey, Puch, Sachs, Sears, Sparta, 74-85 Tomos, and others. These US models all had threaded holes for brake light switches. Most Euro and Canada models did not have brake light switch holes. 

The brake cable holes on both sides have two versions, M6 threaded bottomless (Peugeot style), or 7mm plain hole with bottom (non-Peugeot style). 

These controls on US models all had ball-end levers except for Sears Free Spirit.

 

 


Magura-clone right control

Magura-clone right control

Magura-clone left control

Magura-clone left control
no start lever (Tomos type)

Magura-clone “Wrap Around” black controls are used on 1979-85 Tomos Silver Bullet. They are made in Yugoslavia to be Magura-compatible. 

Black Magura Levers

Magura-clone levers

The brake cable holes are 7mm plain with bottoms. 

 

 

 

 


Magura late silver left control

Magura late left control

Magura late silver right control

Magura late right control
shown with no grip

 

Magura “Late Wrap Around” silver controls are used on 1980’s Colombia, Hercules, Murray, Puch, Sachs, 79-83 Trac, and others. The housings are thicker and less rounded. The left has a mirror hole. US models had threaded holes for brake light switches. But most Euro and Canada models did not have brake light switch holes. In these photos you cannot tell if there are brake switch holes or not.

The brake cable holes on both sides have two versions, M6 threaded bottomless (Peugeot style), or 7mm plain hole with bottom (non-Peugeot style). 

 

 


Magura late black right control

Magura late right control

Magura late black left control

Magura late left control

Magura late black Tomos right control

Magura late right control
Tomos A3 choke button

Magura “Late Wrap Around” black controls are used on 80-83 Puch Maxi, 80-85 Sachs (Hercules) and others.

The brake cable holes are 7mm plain with bottoms. 

 

 

 

 


Puch-Magura “Sliding Block” black, used on 78-86 Puch deluxe models. 

Most of these are the early, common kind with a screw on the slider holding holding the cable wire. The cable wire itself has no upper end piece. It  takes a “universal” or “single ended” throttle cable.

Some of these are the late, uncommon kind with no screw on the slider. Instead the cable wire has an upper end piece 3mm “inline barrel” soldered onto it. The cable is specific to that set-up, and is “double ended”.

The brake cable holes are 7mm plain with bottoms.

Puch Magura sliding block controls

Puch Magura sliding block black controls

Magura slide throttle late (no screw on slider) and early (screw on slide)

Left: Slider with a pinch screw for Puch 1978-83
models Maxi Luxe, Newport, Sport, Magnum
(takes a single-ended throttle cable)
Right: Slider with no pinch bolt for Puch 1984-86
all models. Housing has a slot for cable.
(takes a double-ended throttle cable)

xx

 

 

 

 

 

 

 

 

 

 

 

 


Service Information

The tongue and groove lock together, but only when they are off the handlebar.

Magura Wrap-Around Throttle

As mentioned above, the pieces snap together, but only when removed from the handlebar.

Twist tube: The throttle housing has a tongue that goes into a groove in the twist tube. The two pieces are first locked together while off the handlebar, and then slid on as a unit. Then the twist tube is kept from moving sideways. 

Thumb trigger: Not all mopeds have this, but all the wrap-around housings have a provision for it. This is also called a choke lever or a decomp lever. The trigger has half-circle-shaped posts that slide into slots in the throttle housing, but only when off the handlebar, and in the “squeezed past max” position. Once on, the handlebar prevents it from detaching.

Tomos A3 auto choke thumb button: This button, when pushed in, lets the throttle cable go all the way slack for cold starting.  When it is not pushed in, it allows the cable to stay a little taut for normal idling. Idle speed is adjusted by the tightness of the throttle cable, at the handlebar by the Magura type cable adjuster.

Installing a throttle cable on a Magura wrap around type throttle

Installing a throttle cable on a Magura wrap around throttle

 

Installing a throttle cable: With an original Magura twist tube, the cable installs from the outer side, just behind the grip. Turn the grip forward to the closed position. Locate where the cable end is. Peel the flange of the grip there back with your thumb, and hold it there. With the other hand, place the sideways barrel end of the throttle cable into the cavity. Lay the wire over the ridge, and wrap it around the curved guide. When pulled taut it should fall into it’s groove. The throttle should pull the wire and move free.

With a Magura-clone twist tube, the cable installs from the inner side. So the twist tube has to be removed. That means the whole throttle has to be removed from the handlebar. But the cable is more protected.  

 

How to install the throttle cable:

 

 

 

 

 

 

 

 

 

 

 

 


Worn throttle cable groove: The curved cable guide groove can become worn in the middle. It can become so bad that the throttle feels like a hack saw and makes a ripping sound like a zipper. When that happens the cable will soon be cut through and break. The cause of the worn groove is lack of lubrication. Moped cables and controls need oil occasionally.

Worn Magura wrap-around throttle housing

Restoring a worn groove

Restoring a worn groove

 

 

 

 

 

 

 

 

 

The remedy is to re-cut the bottom of the curved guide. The best tool is a masonry hack saw blade. It has the exact width and round shape. The linear saw is moved in a curved motion. The bottom of the channel is visually checked every few strokes, to see what areas need more cutting.

 

 


Installing a Magura brake lever spring.

 

 

Magura throttle brake and choke cable exposed lengths

Tri-Flow lubricant

 

Lubrication: Lube the cables and controls with a drip oil, like 3-in-1 or Tri Flow or any high tech lubricant. Tri Flow is thin so it penetrates in and clings to metal, like WD40. But after awhile when most of the liquid drys up, it leaves behind microscopic Teflon particles embedded in the metal surface.   

Making custom cables: Here are the distances of the exposed cable wires, for Magura wrap-around type moped controls. 

 

 


Myrons Collection of Moped Publications

April 27, 2009

Point to see the title. Click to see the image. Click to enlarge to full size. Click the back arrow to return to menu.

[nggallery id=9]


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.

 

 

 


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    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