Bing Jets

October 26, 2011

Bing jets are in Bing and some Encarwi carburetors.

3.5 mm thread (M3.5-0.60) Bing jets are on Puch-Bing, Solo-Bing, Kreidler-Bing, and Encarwi.

4.0 mm thread (M4.0-0.70) Bing jets are on Sachs-Bing, late 80’s AD-Bing and 90’s Korado-Bing.

Myrons Mopeds Bing Jet Sizes Chart

These jets are on other 1970’s – 80’s small engines with Bing carburetors. 

The Bing 3.5 main jets are also idle jets on some bigger Keihin carbs.

The Bing 4.0 main jets are also idle jets on some bigger Dellorto carbs

Original Bing jets are numbered wrong, in a sense. The jet number is not the millimeter size. An original Bing 54 is actually 0.51 mm, not 0.54. This was discovered this in the early 2000’s when aftermarket Bing jets came out. 200 jets were carefully measured with precise wire guages, and then plotted on the graph at right. The original jets (and the first A&R generics) form one line. All other generic jets form a different line.

Generic Bing jets are numbered correctly. The size they say is the millimeters they are. So a generic Bing 54 is actually 0.54 mm.











           Bing Jets (3.5 mm) 

 part #   maker   jet#  close to    measured size      price     applications

78drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————
  custom #00 =Bing46 0.0173″=0.440mm  $15.0  soldered, 78-drilled, then filed with .017 guitar string
Bing46  original #46 =Bing46
0.0175″=0.445mm  $18.0  76-83 Tomos early A3 models (30, 25, and 20mph)
3.5×45  custom #00 =Bing47 0.0177″=0.450mm  -N/A–
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
3.5×46  custom #00 =Bing48 0.0181″=0.460mm  -N/A–
Bing48  original #48 =Bing48 0.0182″=0.462mm  $15.0  78-80 Puch (2-spd hi torque Ø12 carb 20mph)
3.5×47  custom #00 =Bing49 0.0185″=0.470mm  -N/A–
Bing50  original #50 =Bing50 0.0188″=0.478mm    none  76-78 Batavus (Laura M48 Ø8 carb 20mph)
3.5×48  generic #48 =Bing51 0.0190″=0.480mm  $4.00
3.5×49  custom #00 =Bing52 0.0190″=0.490mm  -N/A–

Bing52  original #52 =Bing52 0.0194″=0.493mm  $5.00  76-78 Batavus (Laura M48 Ø8 carb 25 mph)
3.5×50  generic #50 =Bing53 0.0195″=0.500mm  $4.00
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————

Bing54  original #54 =Bing54 0.0200″=0.508mm  $5.00  74-83 Puch (1-spd alum. cylinder, Ø12 carb 2.22, 20mph)
3.5×51  generic #51 =Bing54 0.0201″=0.510mm 

3.5×52  generic #52 =Bing55 0.0204″=0.520mm  $4.00
Bing56  original #56 =Bing56 0.0206″=0.523mm  $11.0  77-80 Batavus M48 and M56 (30), 80-83 Trac M56 models
3.5×53  generic #53 =Bing56 0.0209″=0.531mm  none 
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————
3.5×54  generic #54 =Bing57 0.0212″=0.540mm  $4.00
Bing58  original #58 =Bing58 0.0213″=0.541mm  $10.0  78-83 Puch (2-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×55  generic #55 =Bing59 0.0217″=0.551mm  $4.00
3.5×56  generic #56 =Bing60 0.0220″=0.561mm  $4.00
Bing60  original #60 =Bing60 0.0222″=0.564mm    none  78-83 Puch (1-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×57  generic #57 =Bing61 0.0224″=0.571mm  $4.00
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————
3.5×58  generic #58 =Bing62 0.0228″=0.580mm  $4.00
Bing62  original #62 =Bing62 0.0229″=0.582mm  $7.00
3.5×59  generic #59 =Bing63 0.0232″=0.591mm  $4.00

Bing64  original #64 =Bing64 0.0234″=0.594mm  $6.00  74-83 Puch (1-spd al cyl Ø14 carb 2.22 needle jet 30mph)
3.5×60  generic #60 =Bing64 0.0235″=0.600mm  $4.00
Bing66  original #66 =Bing66 0.0239″=0.607mm    none
75drill   custom #00 =Bing48 0.024″ = #73 drill
3.5×61  generic #61 =Bing65 0.0240″=0.610mm  $4.00

3.5×62  generic #62 =Bing66 0.0244″=0.620mm  $4.00
Bing68  original #68 =Bing68 0.0248″=0.630mm   none   78 Sears (1s al cyl Ø14 carb 30mph), Kreidler (30mph)
3.5×63  generic #63 =Bing68 0.0248″=0.630mm  $4.00
75drill   custom #00 =Bing48 0.025″ = #72 drill
3.5×64  generic #64 =Bing69 0.0252″=0.640mm  $4.00

Bing70  original #70 =Bing70 0.0254″=0.645mm    N/A   84-86 Puch Cobra (Ø14 carb, 2.17 needle jet 25mph)
3.5×65  generic #65 =Bing71 0.0256″=0.650mm  $4.00
75drill   custom #00 =Bing48 0.026″ = #71 drill
3.5×66  generic #66 =Bing72 0.0260″=0.660mm  $4.00

Bing72  original #72 =Bing72 0.0260″=0.660mm    N/A   84-86 Puchs had bigger main jets, but smaller needle jets.
3.5×67  generic #67 =Bing73 0.0264″=0.670mm  $4.00

Bing74  original #74 =Bing74 0.0267″=0.678mm    N/A   1990’s Puch remakes also had 70’s jets, 2.17 needle jets.
3.5×68  generic #68 =Bing74 0.0268″=0.681mm  $4.00
3.5×69  generic #69 =Bing75 0.0272″=0.690mm  $4.00

Bing76  original #76 =Bing76 0.0273″=0.693mm  $6.00
3.5×70  generic #70 =Bing77 0.0278″=0.705mm  $4.00
75drill   custom #00 =Bing48 0.028″ = #70 drill
3.5×71  generic #71 =Bing78 0.0280″=0.715mm  -N/A--

Bing78  original #78 =Bing78 0.0280″=0.711mm    N/A
3.5×72  generic #72 =Bing79 0.0283″=0.725mm  $4.00

Bing80  original #80 =Bing80 0.0287″=0.729mm    N/A
3.5×73  generic #73 =Bing81 0.0287″=0.735mm    none
3.5×74  generic #74 =Bing82 0.0291″=0.745mm  $4.00

75drill   custom #00 =Bing48 0.0292″ = #69 drill —————————————————————
Bing82  original #82 =Bing82 0.0292″=0.742mm  $7.00 2000’s Bing Ø15 carb with smaller 2.17 needle jet
3.5×75  generic #75 =Bing83 0.0296″=0.755mm    none
Bing84  original #84 =Bing84 0.0300″=0.762mm    none 1978-79 Puch Magnum X


cleaning a #25 jet

       Bing Jets (4.0 mm) 

At right, the smallest of the small. The #25 pilot jet is bigger than wire wheel wires, but smaller than wire brush wires in the background. It’s three hairs wide!

part number  maker  jet#  close to    measured size      price     applications

Tomos243222 Dell.  #25 =Bing27 0.0107″=0.272mm     $8  Tomos A55 pilot (idle) jet
Tomos243110 Dell.  #29 =Bing31 0.0124″=0.314mm     $8   same as Tomos #25 idle jet “cleaned” with #80 drill
D1486-030 Dellorto #30 =Bing33 0.0128″=0.325mm     $8  good for A55 pilot jet, mix screw 1 turn more out
77drill   custom #00 =Bing48 0.0135″ = #80 drill —————————————————————

D1486-032 Dellorto #32 =Bing35 0.014″ = 0.355mm     $8  same as drilled with #80 drill, sub for A55 pilot jet
77drill   custom #00 =Bing48 0.0145″ = #79 drill —————————————————————

D1486-035 Dellorto #35 =Bing39 0.0149″=0.378mm    N/A
77drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————

D1486-040 Dellorto #40 =Bing45 0.0170″=0.431mm     $8
4mBing45 Bing orig #45 =Bing45 0.0171″=0.434mm    N/A   Sachs 504/1A DK (19mph)
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
4mBing48 Bing orig #48 =Bing48 0.018″ = 0.46mm      $8
D1486-043 Dellorto #43 =Bing49 0.0182″=0.462mm    N/A
4mBing50 Bing orig #50 =Bing50 0.0183″=0.465mm     $8  Sachs 504/1B and 505/1B (Ø10 carb 20mph)
D1486-044 Dellorto #44 =Bing51 0.0187″=0.475mm    N/A
4.0×48 000 generic #48 =Bing51 0.0189″=0.480mm
D1486-045 Dellorto #45 =Bing51 0.0190″=0.483mm     $8
4mBing52 Bing orig #52 =Bing52 0.0194″=0.493mm    $8.00 Sachs 504/1A and 505/1A (Ø12 carb 30mph)
D1486-046 Dellorto #46 =Bing52 0.0194″=0.493mm    N/A
4.0×50 000 generic #50 =Bing53 0.0197″=0.500mm
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————

4mBing54 Bing orig #54 =Bing54 0.0200″=0.508mm    $8  ’84-86 Puch Austro Daimler (30mph)

D1486-047 Dellorto #47 =Bing54 0.0198″=0.503mm    N/A
D1486-048 Dellorto #48 =Bing55 0.0202″=0.513mm    $8  Sachs 504/1A and 505/1A (without air filter box)
4.0×52 000 generic #52 =Bing56 0.0205″=0.520mm
4mBing56 Bing orig #56 =Bing56 0.0206″=0.523mm    N/A  

D1486-049 Dellorto #49 =Bing56 0.0207″=0.526mm    N/A
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————

D1486-050 Dellorto #50 =Bing57 0.0210″=0.533mm    N/A
4.0×54 000 generic #54 =Bing58 0.0212″=0.540mm
4mBing58 Bing orig #58 =Bing58 0.0213″=0.541mm   $8.00 Sachs 504/1D and 505/1D (Ø12 D-carb 30mph)
D1486-051 Dellorto #51 =Bing59 0.0215″=0.546mm    N/A
4.0×56 000 generic #56 =Bing51 0.0220″=0.560mm
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————

D1486-055 Dellorto #55 =Bing63 0.0230″=0.580mm     $8
4.0×58 000 generic #58 =Bing63 0.0230″=0.580mm
4.0×60 000 generic #60 =Bing65 0.0236″=0.600mm
75drill   custom #00 =Bing48 0.024″ = #73 drill —————————————————————

4.0×62 000 generic #62 =Bing68 0.0244″=0.620mm

D1486-060 Dellorto #60 =Bing69 0.0250″=0.635mm     $8




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





Jet Drills

January 27, 2007


Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.010" (ten thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.011″ (eleven thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

This will help you visualize how small these drills and jets are!

Moped main jets range from 0.018″ (#77 drill) to 0.026″ (#71 drill). 

Moped idle jets, like Tomos A55, are 0.011″ (smaller than #80).

An average human hair is 0.003″ (three thousandths of an inch).

So moped jet holes are 4 to 9 hairs wide!

Shauns well used jet drill container from the 1980's

Shaun’s well used drill container from 1987


Jet Drills: All through the late 1980’s and 1990’s, Shaun (at Royal Cyclery and later at Myrons Mopeds) used the USA-made jet drills to service carburetors. The drill sizes are an American wire gauge. They did not vary in size. Those 20-piece Drill Sets 61 to 80, cost $40 in 2015, $33 in 1998. and $29 in 1987. Some are in clear plastic round dome containers, and some are in conventional metal drill set boxes.



Drill Set 61-80 USA-made

Drill Set USA-made

Jet Drills made in China

Set 1 China-made

China-made Drills: In the 2000’s there were many China made tools sold in “surplus” tool stores. The China made 20-piece Drill Sets 61 to 80, sell for $7 to $10, or one fourth as much. They have an excellent blue plastic container, that only lets out one at a time. But the drill sizes are all wrong. From about 2010 to 2014, Myrons Mopeds sold these inexpensive drill sets, not knowing that the drill sizes were inexact, to say the least.

So although the China sets cost one forth as much, they only have about seven or eight different sizes, and they lack the smaller sizes below 0.4 (or sometimes 0.6) mm. Each set is different.


Jet Drills made in USA

Jet Drills made in USA

Set 2 China-made

Some have poorly made drills, twisted funny, bigger at the cutting end, or lumpy, varying in thickness. Some have poorly made cutting tips, so they might wander, grab and break, or not cut well.

Despite the poor quality and inexactness, the inexpensive drills are still useful for cleaning purposes, but not for measuring and maybe not for drilling. Fortunately, brass carburetor jets are the easiest thing to drill, with a drop of oil and a pilot hole already there.



Micro Drills and Wires for Sale Individually

These drills are measured at the shank (the smooth part). At the cutting edge they are 1 or 2% bigger.

These wires are steel guitar strings, cut into 5 inch lengths. 

“Metric” jets have a number that literally means hundredths of a millimeter, so a 64 jet is 0.64 mm.

Micro Drills for sale

inch   mm/#  price     moped jets that it cleans
0.011   wire     N/A Gurtner Motobecane diffuser – two idle holes (.013)
0.0135 #80  $6.00
0.0145 #79  $5.00
0.0157 0.40  $3.00 Dellorto 38 (.0162), Bing 42 (.0162)
0.016   #78  $4.00 Dellorto 40 (.0168), Bing 44 (.0167)
0.017   wire  $0.50 Dellorto 42 (.0177), Bing 46 (.0175)
0.018   #77  $3.50 Dellorto 44 (.0186), Bing 50 (.0188)
0.019   ——  $2.00 Dellorto 46 (.0194), Bing 52 (.0194)
0.0197 0.50  $2.00 Dellorto 48 (.0202), Bing 54 (.0200), “Metric” 51 (.0201)
0.0200 #76  $3.50 Dellorto 49 (.0207), Bing 56 (.0206), Gurtner 210=52 (.0210)
0.021   #75  $4.00 Dellorto 51 (.0215), Bing 58 (.0213), Gurtner 220=54 (.0220)
0.0225 #74  $5.00 Dellorto 55 (.0231), Bing 62 (.0229), Gurtner 230=56 (.0230)
0.023   ——  $2.00 Dellorto 56 (.0235), Bing 64 (.0234), Gurtner 240=58 (.0236)
0.0235 0.60  $2.00 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 245=59 (.0239)
0.0235 0.60  $1.50 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 250=60 (.0242)
0.024   #73  $3.00 Dellorto 60 (.0247), Bing 68 (.0248), “Metric” 63 (.0248)
0.025   #72  $3.50 Dellorto 62 (.0255), Bing 70 (.0254), “Metric” 65 (.0256)
0.026   #71  $4.50 Dellorto 66 (.0268), Bing 74 (.0267), “Metric” 68 (.0268)
0.0275 0.70 x N/A  Dellorto 70 (.0280), Bing 78 (.0280), “Metric” 71 (.0280)
0.028   #70  $4.00 Dellorto 72 (.0287), Bing 80 (.0287), “Metric” 73 (.0287)
0.0292 #69  $4.50 Dellorto 78 (.0306), Bing 84 (.0301), “Metric” 77 (.0303)
0.030   wire     N/A Dellorto 80 (.0312), “Metric” 79 (.0311), Gurtner K80 (.0311)
0.031   #68  $4.50 Dellorto 82 (.0318), “Metric” 81 (.0319)
0.0315 0.80  $2.00 Dellorto 84 (.0324), “Metric” 82 (.0323)
0.032   #67  $3.00 Dellorto 86 (.0331), “Metric” 84 (.0331)
0.0325  —— $2.00 Dellorto 88 (.0337), “Metric” 86 (.0339)
0.033   #66  $4.50 Dellorto 90 (.0343), “Metric” 88 (.0346)
0.034   wire     N/A “Metric” 90 (.0354)
0.035   #65  $3.00 “Metric” 92 (.0362), Gurtner MB (side mount) diffuser (.0358)
0.0354 0.90  $2.00 “Metric” 94 (.0370)
0.036   #64  $3.00
0.037   #63  $2.50
0.038   #62  $1.50
0.039   #61  $1.50
0.0394 1.00  $1.00


Deluxe 40-piece Micro Drill Set

Jet Drills 80-72 and 71-60

Myron’s Mopeds two case deluxe micro drill set, 80 to 72 (small) and 71 to 60 (large) plus many in-between sizes.
Price none, sorry no more.

Slide clear top plastic until hole is over drill (and pointer is on desired drill number). Only lets one drill out at a time. Never take out more than one at a time, or they can get mixed. The case keeps them organized. If any get lost, dull, or broken, individual drills can be bought at some hardware stores for $3-$4 each.

Useful for sizing to tell how big a jet really is (sometimes they’re drilled out or labeled wrong).

Useful for cleaning varnish or corrosion coating the inside of an old jet. It doesn’t really clean out any other way. The drill is used as a file, held with a needlenose pliers.

Useful for drilling jets to make a new size, as an alternative to buying ones. The drill is held with a needlenose pliers, and the jet is rotated with your fingers, with a drop of oil. To go down in size, fill the hole with solder and re-drill it smaller.




Here is a pin vise, a mini drill chuck, price $8








Other Tools for Cleaning Jets

Using a micrometer to measure a 0.017 wire

Using a micrometer to measure a 0.017″ wire

Guitar steel string 17 thousandths of an inch

Guitar string

Guitar Steel Strings in the smaller sizes are excellent tools for cleaning small holes. Here is a 0.0170 inch steel wire guitar string, perfect for cleaning out a 1974-85 Tomos stock jet size 46 that has a 0.0175 inch hole. A Honda Express NC50 (Keihin) carburetor, has a long brass idle jet tube with a tiny jet hole at the far end, too far for a drill to reach. For that, only a 2 or 3 inch piece of 0.010″ steel guitar string will reach to clean it. Ultrasonic cleaners, carb spray, or soaking are not effective for that. Other examples are a Sachs 52 jet 0.0190 would be cleaned by a 0.018″ wire, or a Motobecane 230 jet 0.023″ would be cleaned by a 0.022″ wire. The wire has to be a little smaller than the hole. Plain steel strings range from 0.008″  to 0.017″ in steps of 0.001″. Wound strings range from 0.017″ to 0.065″. 


Torch Tip Cleaner Set

Torch Tip Cleaner Set

Root Canal Files

Root Canal Files (say ahhh)

Welding Torch Tip Cleaners are another excellent tool for cleaning small holes. The tip has a cutting surface but not the sides. So it is made to clean the hole without widening it.

Wire Feeler Gauge Sets: There are also wire gauge measuring sets that look the same as the torch cleaner set shown.

Dentist’s Root Canal Files are also good for cleaning small holes. Color coded files range from 0.06 to 1.10 mm (0.0024 to 0.0433 inch).