Lower Your Genuine Buddy!

Short Buddy Riders Unite!

We have confirmed that the Scooterworks Low Down rear shock fits on all Genuine Buddys, RoughHouse, Rattler and Black Cat!

Lower your Genuine Buddy by three inches with this seat and rear shock

Our adjustable Scooterworks Low Down shock will lower the Buddy seat height from ½” to 1½”, giving you a new seat height of 28½”.  When this is combined with the Buddy Low Profile seat, the seat height drops an additional 1½”, for an overall drop of three inches, bringing the total seat height down to 27”!

 Lower the seat height on your Genuine Scooter up to three inches.

Installation is a snap.  To fit the Scooterworks Low Down shock on these models, you’ll need just to flip the lower clevis (so the offset is facing outward and the bolt enters from the inside).

 Close up of Low Down Shock installation on a Buddy Scooter.

For heavier Buddy riders, or those who ride two-up, we advise that you adjust the preload higher and set the height of the shock to no lower than a 1” drop, unless you remove the rear fender for added clearance for the fuel valve.  We tested the shock at this setting on a Buddy with a 220lb rider and had no clearance issues.

The RoughHouse low profile seat is due in this spring.

Stock Scooter Roller Sizes & Weights

This chart will continue to be updated as more information becomes available.

Genuine

Model Weight Size Stock Weight
Buddy 50 16 x 13 7.5g/8.5g
Rattler/Black Cat 50 16 x 13 7.5g/8.5g
Rough House 50 16 x 13 7.5g/8.5g
Buddy 125 18 x 14 11.0g
Buddy 150 18 x 14 13.0g
Blur 150 18 x 14 13.0g
Buddy Black Jack 18 x 14 13.0g

 

Kymco

Model Weight Size Stock Weight
People 50 16 x 13 8.5g
People 150 18 x 14 15.0g
Super 8 150 18 x 14  
Super 9 2T 15 x 12  
People 250    
People S 250    
Grand Vista 250    
Xciting 250    
Xciting 250 Ri    
Xciting 500    
Xciting 500 Ri    

 

SYM

Model Weight Size Stock Weight
Citycom 300i 23 x 18 17.0 g
Mio 50 4T    

 

Modern Vespa

Model Weight Size Stock Weight
Vespa LX50 4T 19 x 15.5 6.5g
Vespa ET2 before ’98 16 x 13 8.5g
Vespa ET2 after ’98 19 x 15.5 6.5g
ET4 125 19 x 13.5 11.5g
ET4 125-150 with Leader 19 x 17 10.0g
GT200 21 x 17 10.7g
GTS 250 21 x 17 11.0g
GTSV/GT60 21 x 17 11.0g
MP3 250 21 x 17 11.0g

 

Yamaha

Model Weight Size Stock Weight
Vino 50 2T 15 x 12 6.5g
Zuma 50 2T 15 x 12 6.5g
C3 15 x 12  

 

Honda

Model Weight Size Stock Weight
Metropolitan 16 x 13 7.5g
Ruckus 02-05 16 x 13 7.5g
Ruckus 06-09 16 x 13 7.0g
Big Ruckus 23 x 18  
Elite 150 (old)    
Elite 150 EFI (new)    
Reflex 250 23 x 18 21.0g

Lock Up Your Scooter!

Getting your scooter stolen isn’t nearly as fun as you’d think.  We highly recommend locking up your scoot whenever possible.  Thieves would rather deal with easy targets than try to pry, cut, torch or saw through your lock.  Even if a friendly pole isn’t available, a lock through your rim or your rotor will make their lives a little more miserable.

 

We offer a tasty array of locks, ranging from lightweight and compact to beefy and disturbing.

Beefy chain lock, great for street fighting.
Prima's Heavy Duty Chain Lock
Prima's Thick Cable Lock

 

 

Compact cable lock, fits easily in bags and gloveboxes.
Kryptonite's Compact Cable Lock
The toughest chain lock out there
Kryptinite's Fahgeddaboudit Lock

 

 

Spark Plug Type by Model

Genuine

Model NGK spark plug
Black Cat 50 BR7HS/BPR7HS
Rattler 50 BR7HS/BPR7HS
Buddy 50 BR7HS/BPR7HS
Rattler 110 BR7HS/BPR7HS
Buddy 125 CR7HSA
Buddy 150 CR7HSA
Blur 150 CR7E
Stella B7ES

 

Modern Vespa

Model NGK spark plug
ET2 BR9ES
ET4 CR8E
LX50 CR8E
LX150 CR8E
LXV150 CR8E
Vespa S CR8E
GT200 CR8E
GTS250 CR8E
GTV250 CR8E
GTV300 CR8E
GTS300 CR8E
GTS Super CR8E

 

Vintage Vespa

Model NGK spark plug
49-150cc except GS150 B6HS or B7ES (7 is a cooler plug, 6 is hotter)
GS 150 B6HS or B7ES
160cc and up B6HS or B7ES

 

Piaggio

Model NGK spark plug
Typhoon BR8ES
BV200 CR8E
BV250 CR7E/CR7EK
BV500 CR7E/CR7EK
X9 CR7E/CR7EK
MP3-250 CR7E/CR7EK
MP3-400 CR7E/CR7EK
MP3-500 CR7E/CR7EK

 

Kymco

Model NGK spark plug
Cobra BR6HSA
Super9 LC BR6HSA
Super9 AC BR6HSA
People50 2T BR6HSA
Agility50 4T CR7HSA
Vitality50 4T CR7HSA
People S 50 CR7HSA
Filly 4T CR7HSA
ZX50 BR8HSA
Yup50/Sting BR8HSA
Sento C7HSA
Agility 125 CR7HSA
People S 125 CR7HSA
Super8 150 CR7HSA
People 150 CR7HSA
Bet&Win 150 DPR7EA-9
People S 200 CR7HSA
People 250 DPR7EA-9
People S 250 DPR7EA-9
Bet&Win 250 DPR7EA-9
Grand Vista DPR7EA-9
Xciting 250 DPR7EA-9
Xciting 250Ri CR8E
Xciting 500 CR8E
Xciting 500Ri CR8E
Venox 250 CR8E

 

TGB

Model NGK spark plug
KeyWest BR7HS/BPR7HS
R50X BR7HS/BPR7HS
Delivery50 BR7HS/BPR7HS
Delivery150 CR7HSA
Sunset50 BR7HS/BPR7HS
Sunset150 CR7HSA
LaserR5-50 BR7HS/BPR7HS
LaserR9-150 CR7HSA

We’ve made every effort to ensure the accuracy of this chart.  Always compare your plug with the new one before installing, and check your plug for proper color periodically.

Battery by Scooter Model

Below, you’ll find a number of scooters and the batteries they take, as well as links to Scooterworks’ Product Pages to make ordering a replacement battery quicker and easier. More scooters and batteries will be added to the list below as that information becomes available, but you can always visit Scooterworks‘ home page or call 1.888.968.3772 for up-to-the-minute information from one of Scooterworks customer service representatives.

Untitled Document

 

 

Genuine

Model Battery
BlackCat/ Roughhouse TX4L-BS
Rattler 50 TX4L-BS
Roughhouse 50 TX4L-BS
Buddy50 TX4L-BS
Rattler 110 TX5L-BS
Buddy 125 TX7A-BS
Buddy 150 & 170i TX7A-BS
Blur 150 TX7L-BS
Blur 220 TX9-BS
Stella B9-B

 

Modern Vespa

Model Battery
ET2 TX4L-BS
ET4 B9B/TX12-BS
LX50 B9-B
LX150 TX12-BS
LXV150 TX12-BS
Vespa S TX12-BS
GT200 TX12-BS
GTS250 TX12-BS
GTV250 TX12-BS
GTS Super TX12-BS

 

Vintage Vespa

Model Battery
60s-70s battery models without turn signals B39-6
70s battery models with turn signals (except Rally) 6N11A-1B
P200E, P125 without electric start 12N5.5-3B
PX150, PX200 with electric start B9-B
GS150 (unique)84647

 

Piaggio

Model Battery
X9 TX12-BS

 

Kymco

Model Battery
Cobra TX4L-BS
People S 50 TX7A-BS
People S 125 TX7A-BS
People S 200 TX7A-BS
People 250 TX7A-BS
People S 250 TX7A-BS

 

TGB

Model Battery
KeyWest TX5L-BS
LaserR9-150 12N9-4B-1

 

TGB

Model Battery
Vintage Chetak (pre-1990)
6N11A-1B

 

Modern Chetak B9-B
Legend B9-B

 

Battery Acid (Electrolyte) Levels

Volumes of acid that go in an empty battery of each type (sealed batteries):

TX5L-BS (B12K1) – 6.8 ml per cell

TX4L-BS (B12K2) – 5 ml per cell

TX7A-BS (B12BUD125) – 10.3 ml per cell

TX12-BS (B12ET4) – 15.5 ml per cell

 

**NOTE**  Batteries that ship with acid cannot be shipped via air.

Bulb and Lighting Charts (by Make/Model)





Untitled Document


The part numbers on this page assume stock/factory light fixtures and standard (OEM) wiring. Bulb types and part numbers may change with aftermarket assemblies or upgraded 12V electrics.

The following tables are organized by make/brand. Scooterworks part numbers are listed (in parentheses) where applicable. More makes/models will be added as the information becomes available.

To browse through Scooterworks‘ comprehensive online catalog for replacement parts or aftermarket/custom lighting solutions click here.

Type Key B = Bayonet style bulb (standard push in and turn type bulb)
F = Festoon bulb (looks like a fuse)

Genuine

Model Headlamp Pilot Light Stop Light Tail Light Speedo Light Turn Signal
Genuine Stella 2T/4S

Halogen H4 35 Watt (B12H4)
Headlight Assy. (582946)

    Taillight Assy. (B6F5)   RR Assy. (230339)
LR Assy. (230339)
RF Assy. (163256)
LF Assy. (162817)

 

Vintage Vespa

Model Headlamp Pilot Light Stop Light Tail Light Speedo Light Turn Signal
Vespa 125 VN1-2 6v-25/25w (B6HLS) F 6v-10w (B6F10)   F 6v-5w (B6F5)    
Vespa 150 VL1 6v-25/25w (B6HLS) F 6v-10w (B6F10)   F 6v-5w (B6F5)    
Vespa 125 VNA 6v-25/25w (B6HLS) F 6v-5w (B6F5)   F 6v-5w (F5)    
VNB1 125 Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5)    
VNB1 125 Non-Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-5w (B6P5) F 6v-5w (B6F5)    
VNB2-4 125 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5)    
VBA 150 (Model #76051+) Battery 6v-25/25w (B6HLS) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  

VBA 150   Non-Battery

6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-5w (B6P5) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
VBB1 150 (Model #71000-) Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
VBB1 150 (Model #71001+) Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
VBB1 150 Non-Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-5w (B6P5) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
VBB2 150 Non Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GL 150 VLA1 Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GL 150 VLA1 Non Battery 6v-25/25w (B6HL25) F 6v-5w (B6F5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GS 150 VS1 Battery 6v-25/25w (B6HLS) F 6v-5w (B6F5)   F 6v-5w (B6F5)    
GS 150 VS2 Battery 6v-25/25w (B6HLS) F 6v-1.5w   F 6v-5w (B6F5) F 6v-1.5w (B6FSP)  
GS 150 VS3-4 Battery 6v-25/25w (B6HLS) B 6v-1.5w F 6v-10w (B6F10) F 6v-5w (B6F5) F 6v-1.5w (B6FSP)  
GS 150 VS 5 Battery 6v-25/25w (B6HLS) B 6v-5w (B6P5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GS 160 VSB1 Battery 6v-25/25w (B6HL25) B 6v-5w (B6P5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GS 160 VSB1 Non Battery 6v-25/25w (B6HL25) B 6v-5w (B6P5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Vespa 50 V5A1 V5SA1 V5SS 6v-25/25w (B6HL25) B 6v-10w (B6P10) *F 6v-10w (B6F10) *F 6v-5w (B6F5)    
Vespa 50 V5A1 No Stop Light 6v-25/25w (B6HL25) B 6v-5w (B6P5)   F 6v-5w (B6F5)    
Vespa 90 V9A1 V9SS1 6v-25/25w (B6HL25) B 6v-5w (B6P5) *F 6v-10w (B6F10) *F 6v-5w (B6F5)    
Vespa SS90 V9SS2 6v-25/25w (B6HL25) B 6v-5w (B6P5) F 6v-10w (B6F10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Primavera 125 VMA1 VMA2 & ET3 6v-25/25w (B6HL25) B 6v-5w (B6P5) *F 6v-10w (B6F10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Super 125 VNC 6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Super 150 VBC 6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP) (B6TS-US Model)
GT 125 VNL2 6v-25/25w (B6HL25) B 6v-5w (B6P5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
GTR 125 VNL2 6v-25/25w (B6HL25) B 6v-5w (B6P5) B 6v-10w (B6P10) F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Sprint (Veloce) 150 VLB1 6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP) (B6TS-US Model)
Super Sport 180 VSC1 Non Battery 6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP)  
Super Sport 180 VSC1 Battery 6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP) (B6TS-US Model)

Rally 180 & 200 VSD1 VSE1

6v-25/25w (B6HL25) B 6v-5w (B6P5) *B 6v-10w (B6P10) *F 6v-5w (B6F5) F 6v-0.6w (B6FSP) (B6TS-US Model)
P125 VNX, 150 VLX & 200 VSX 12v-25/25w (B12HL/Euro, 174873/US Model)   (dual filament bulb B122W) (dual filament bulb B122W) 12v-3w 12v-21w (B12TS)
P150 VLX 12v-25/25w (B12HL/Euro, 174873/US Model)   (dual filament bulb B122W) (dual filament bulb B122W) 12v-3w 12v-21w (B12TS)
P200 VSX1T 12v-25/25w (B12HL/Euro, 174873/US Model) (dual filament bulb B122W) (dual filament bulb B122W) 12v-3w 12v-21w (B12TS)

B6


Engine: 5-port LML Engine Install (FAQs)

The replacement 5-port engine from LML is a popular Scooterworks product for vintage Vespa restorations – and for good reason: it’s usually a faster, smoother, and more reliable motor than the original!

Below, you’ll find some of the most common questions asked about the 5-port engine’s installation.


Q1. HOW DO I HOOK UP THE WIRING?


This is the most common question when installing the LML engine into a vintage Vespa without battery or signals. The LML stator is a “single” output stator, which means that all of the power comes through one wire, runs through the regulator, to the switch, and is then distributed to the bulbs and horn from there.

NOTE: most US-model vintage Vespa scooters before MY1974 used a three wire output. On these (-’74) models, the stator had three wires (either 2 yellow and 1 red, OR 1 yellow, 1 blue, and 1 green) to feed the lighting system. This style of wiring will not work with the single wire stator, since most did not have an inline regulator and the power from the stator will not be distributed correctly. In order to properly connect the electrical system, a wiring conversion kit (shown, below) is required.

Wiring Conversion Harness Kit Image

Q2. WHY ARE THERE PARTS LEFT OVER?


LML engines are shipped with some electrical components: a silver box (regulator), a red box (CDI). If you purchased the wiring harness kit, you will only be using the blue CDI/coil unit and the components that came with the conversion kit. These other components (the silver and red boxes) will not be used.

 


Q3. HOW DO I CONNECT THE VOLTAGE REGULATOR?


There are three posts on the voltage regulator supplied with the EIKHK harness (above). Two of the posts are closer together and one is “separate”. That separated post is the ground, connect the black wire there. The two posts closer together are both “positive”, connect the blue wire here (either one).

 


Q4. WHERE DO I CONNECT THE GRAY COIL ON THE BACK OF THE ENGINE?


This is another component of the engine that will not be used for the install. The blue CDI/coil unit mentioned above contains everything you need. Remove the grey coil and set it aside (you never know when you’ll need extra electrical parts!).

TIP: when you take the coil off, unscrew the plug wire from it and use it on the new CDI/coil combo. Use the wiring diagram (below) as a reference.

 

These are just the most common questions regarding the LML 5-port engine install – there are many more that you may have, so don’t hesitate to call us at 1-888-968-3772.

5-port LML Engine Run-in

RUN-IN INTRODUCTION

The first 500 miles of your new 5-port LML engine‘s life are without a doubt the most important. The parts are all new, and they all need a few heat cycles to expand and contract and settle into their correct operating tolerances. Taking your time and getting the run-in right will help to ensure a long, reliable life from your new engine.

PRO TIP

Avoid over-straining your new engine with excessive speeds/rpm, and try to keep (more or less) to the speeds, below.

  • 1st Gear : 0-6 mph
  • 2nd Gear : 7-12.5 mph
  • 3rd Gear : 12.5-22 mph
  • 4th Gear : 22 + mph

Also, be sure to vary the bike’s speed while cruising, rather than running “steady state” or simply laying on wide-open-throttle (WOT) for long periods of time – this will allow the engine to break in properly under a variety of load conditions.

Be sure, as well, to allow 5-10 minutes of “cool-down” time for each hour of steady use, and check to ensure that the gear box oil stays at the recommended levels.

During engine break-in, it’s also advisable to check and fine-tune your engine’s carb jetting. CLICK HERE for more carb jetting tips, and feel free to call 1-888-968-3772 with any questions you might have.

Carburetor Jetting 101

Getting the most out of a scooter’s carburetor jets is a tough thing for many people. Carb jetting is often part science, part guesstimate, part trial and error. Without a dynamo-meter and some pretty advanced tools, nobody can tell you exactly which carb jets will extract the maximum performance from your hardware, especially if you’ve created a “one-of-a-kind” machine with a series of aftermarket performance upgrades.

That doesn’t mean there’s nothing to learn and that you can’t – through trial and error – find the right jetting on your own. With that in mind, here’s a (very) basic tutorial on the theory behind proper jetting.

Don’t forget: if you can’t find what you’re looking for here, don’t hesitate to call Scooterworks’ customer support at 1-888-968-3772.
________________________________________

CHOOSING THE RIGHT JETS
________________________________________

Dellorto Carb Jet

Carburetor jets are small brass fittings (above) that go in the carburetor and have very precisely-bored small holes in them for fuel and/or air to pass through. The size of these holes will determine your fuel to air ratio, and therefore how rich or lean your mixture is.

Most scooters have at least two jets in their carbs. Large frame vintage Vespas have four: a main jet, an atomizer (mix tube), and an air jet make up the main jet “stack.” There’s a separate idle jet too. Each of these is offered in different “sizes” (really hole sizes). It’s important to know what each means.

If your bike is stock, Scooterworks recommends original, factory-spec carb jets. Those settings were selected at the factory for maximum drivability and emissions compliance, and should work fine for you. If you live near sea level, that is. At higher altitude, the air is “thinner” (less oxygen dense) and with smaller jets may be required to get a proper air/fuel mixture.

If you have a factory-spec. scooter and spend most of your time in a high-altitude riding environment (Denver, Mexico City, etc.) start out by trying a jet that is one or two sizes smaller than the factory “sea level” jet.

If you’ve just installed a performance exhaust, try a jet that is one or two sizes larger than stock as a baseline. If you’ve installed a Malossi cylinder kit on your Stella (for example) or done other extensive performance upgrades, go bigger yet!

If you can’t tell whether or not you’ve selected the right jets based on your riding experience, your spark plug can be an effective indicator of how you’re doing. Start with a fresh plug and go for a short ride, then remove your plug and check the tip, which should be chocolaty-brown color. If it’s black and sooty, you’re running too rich (the jet is too big) and need to trim back the fuel (with a smaller jet). If the plug’s tip is white or “salt-and-pepper”, you’re running too lean (the jet is too small) and need more fuel.
TIP No. 1: with your new jet installed, run your scooter’s throttle 3/4 of the way open, then check the plug.
TIP No. 2: after you’ve tried No. 1, repeat the process at 1/4 throttle to determine if your idle jet is the correct size.

For scooters with a needle on the slide, there is usually an adjustment for the needle height in the slide which determines the fuel mixture in the middle 1/3 of the throttle range. You can do a third ride test with the throttle at 1/2 open to determine this mixture. If it’s too rich, lower your slide a notch. If it’s too lean, raise it.

For scooters without a needle on the slide, the adjustment process is a bit different. If you experience bogging or poor acceleration while you’re riding, the idle jet is probably the wrong size. Try adjusting the air mixture screw first (which serves as a fine adjustment tool for the idle jet), and if the problem doesn’t “adjust away”, change the jet size and try again.
________________________________________

LARGE FRAME VESPA
________________________________________
Understanding proper jet selection for large frame Vespas requires identifying a number of components within the carb, which include …
MAIN JET STACK
– the larger screw-in brass jet (made up of three sections) that regulates fuel/air mixture at the “top” 1/3 of the throttle range (66-100% throttle).

MAIN JET
– the small, cone-shaped jet at the bottom of the main jet stack. These are available in various sizes, ranging from 82-165. Most vintage Vespas will use one in the 85-116 range, although high-performance and race-tuned engines may require much more fuel and use much bigger jets. The higher the number, the larger the jet and the more fuel will flow through to the engine.

ATOMIZER (mix tube)
– located in the center of the main jet stack, it has small holes in the sides. The rating on this type is BE1-BE5. These ratings don’t seem to have any rhyme or reason. For example, a BE4 does not necessarily let in more fuel than a BE2. Most people leave this stock and work with the main and air jets.

AIR JET
– located the top of the stack, with a slot for a screwdriver to make fine adjustments. The hole that goes through it allows air into the jet to pre-mix with the fuel in the atomizer. These are available in 120, 160, and 185 sizes. As before, the higher the number, the larger the jet and the more fuel will flow through to the engine.

IDLE JET
– the smaller jet which is screwed in next to the main jet stack, the idle jet regulates fuel/air mixture at the bottom 1/3 of the throttle range (idle-33% throttle opening). A combination of the idle jet and the main jet handles the middle 1/3 (34-65% opening). If your idle jet is too big or too small, it can create a “flat spot” in the scooter’s acceleration.

Unlike the other jets on this list, idle jets have two numbers – the first number is the size of the bore that allows fuel in, and the second is the size that allows air in. Some common idle jet sizes are: 38/120, 42/160, 45/120, 45/140, 48/160, 50/120, 55/160. So a 45/120 jet would run richer than a 45/140, because the 120 allows less air to pass. To make things more complicated, some vintage Vespas came with “plugged” idle jets, which have no air hole (these are available in sizes 42 and 50).

________________________________________

SMALL FRAME VESPA
________________________________________
Small Frame Vespas have only two jets: a main jet (that the needle passes through), and an idle jet. The small frame’s main jets are available in various sizes ranging from 37-88, but the idle jets are available in only two sizes: 42 and 45.

From the factory, Vespa 50 and 90 use a size 42 idle jet, while the Primavera and ET3 models use a 45.