Mobile Phone? Try our mobile friendly site here:


139QMB 50cc Performance

139QMA, 139QMB, QMB139 50cc 4T OEM 139QMB -50cc Stock Parts 4T Also known as the GY6 50cc. It also goes by several other names such as 50QTB. This Chinese 49/50cc engine is used on many of the 4-stroke imported scooters including the new KYMCO 4 stroke units. Some common brands and names being imported are: Shanghai Shenke, EVO 50cc, Zongshen Metro 50cc, Baja Powersports (PEP BOYS made by Zongshen) Baja SC50, Strada RX 50 (4 stroke) Powersports Factory, Jalon JL50QT-21, Falcon and JL50QT-15, JL50QT-16 , Pantera Freedom, Fusion and Retro, Verucci VC50TS-3M, Sunl SL50QT-16, SL50QT-16, SL50QT-18, SL50QT-2, SL50QT-3, Roketa Bahama, Maui, Sicily, Tank, Baotian 50QT-9, Baotian, 50QT-11, Dotera 50QT-11, Jalon JL50QT-18, Sinski XSJ50QT-6, Sinski XSJ50QT-B, Taishan Commuter, Baja motorsports SC-50 sun city, primo,  Taishan Sport Zhong Hu 50cc 4t This kit will fit most 4 stoke 50cc horizontal style (139QMB) Scooter, Moped, ATV 4-stroke air-cooled engines / motors that are being made and imported from Asia, China, Taiwan, Japan, Korea, etc. like kymco agility , baotian This kit will fit : BAOTIAN BT49QT-2 BAOTIAN BT49QT-7 BAOTIAN BT49QT-9 BAOTIAN BT50QT-9 BAOTIAN BT50QT-11 BAOTIAN Ecobike BENZHOU YY50QT BENZHOU City Star 50 BUFFALO Wind ERING Sprint 50 JIN LUN JL50QT KARCHER KM 50 Kreidler Flory 50 Kymco Agility 50 Kymco Agility MMC 50 Kymco Filly 50 Kymco Vitality 50 KYMCO Filly KYMCO Nexxon 50 KYMCO People KYMCO Super 8 KYMCO Vivality KYMCO NEW DINK 50 KYMCO Yager KYMCO Yager GT MSK Ecobike 50 PEUGEOT V-CLick REX Capriolo 50 REX Flory REX RS 450 REX RS 500 REX Off Limit 45 RIEJU Paseo 50 RIEJU Toreo 50 Sachs 49er 50 Sachs Bee SANILI TS50QT-4 QUINGQI QM50QT-6A XINLING ZHONG YU 50 QT-5 ZHONG YU 50 QT-7 ZHONG YU ZY 50QT ZHONGSHEN Wind 25/50 ZHONGSHEN ZS50QT-4 50, Fly Scooters, VIP, Peace, Roketa, United Motors, TGB, TNG, Benelli, PGO, Tomos Nitro, Kymco, Baccio SPD 50cc, Icebear Maddog 50cc, and many more..... this list is continually growing.
Note: 139QMA and 1p39qmb is the same as 139QMB

Performance Big Valve cylinder head assembly
Unbelievable performance gain not found anywhere. Don't be fooled by other so called "performance" big valve heads. These are the real deal, fully manufactured and hand modified in Taiwan and not China.  Original valves in standard heads are only 15mm exhaust, and 18mm intake. These now have 19mm exhausts, and 21.5mm intakes, matched and machine ported with 3 angle valve seats. We have three options available: Complete assembled heads as shown in the picture here. Option two is with a matched rubber manifold and whopping 24mm carburetor, all matched and ready for 50-60mph scooter fun! Option 3 is big 24mm carb with all metal intake manifold. We'd recommend using our 47mm big bore kit or larger for a nice match and full potential. Also, be sure and measure the valve to piston clearance as these valves are much larger than original, if you don't, you could bend the valve. $149.95 and $174.95 and $194.95. Can't get even a port job done for that little! 
Which kit?
44mm performance stroker crank
 Holy Moly! Just when you thought Scrappy couldn't pull anything else out of his hat! Here is a quality Taiwanese made ScrappyDog 44mm stoker HD crankshaft. Direct bolt in with no modifications necessary in the bottom end. Good quality Taiwan bearings in mains and big end. This honker will yield you more displacement over the 39mm stock stroke crank depending on what size big bore you've installed also, giving you the super grunt and get up and go you deserve. As anyone that would attempt to install this themselves knows, you will have to raise the cylinder in order to accomodate, and of course always check valve to piston clearances. Only available here for this unbelievable low price. $189.95 and in stock, but for how long? SSP-G Quality
Performance roller polygon sliders 16x13
These are probably the best bang for the buck if your still using those old round rollers in your variator. These will spread the load pressure to help broaden the range of variations as sticking is greatly reduced. So in the end, you will get the performance of a lighter and heavier weight roller, in one package, and last longer to boot. Just as good as Dr. Pulley, but much better price. $19.95  These come in 4g, 5g, and 6g now. Lighter weight give you more engine revs.
choose your weight
Performance variator roller set 16x13
Here you go, it's time to get those old rollers replaced, or you've done some modifications and want to get your scoot in tune. Rollers are the way you set the engine speed. Lighter weight raise engine speed, heavier weights lower engine speed. Be careful, higher is not always better as you can rev right past your torque curve and just spin out without any thrust. Too heavy a weight and you will be below your torque curve. Use rollers to experiment with the proper weight can be very rewarding. These are quality copper fine finish rollers that are far superior to original. These come in 4g-8g. *We now stock 1/2 weight rollers!* Quality at wholesale pricing. Only $9.95
choose your weight roller
High performance variator
Best variator on the market right now for your 50cc fourstroke chinese 139qmb and Honda DIO. This has a larger 79mm drive face (larger than stock), steeper roller ramps, extended glide rails for more travel, and slider rollers already installed, along with performance glide bushings and coated ramp plate. Need we say anymore? $69.95 These come in 4, 5, and 6g sliders. Lighter weight gives you more engine revs. 
choose your weight

Here is a video on how to install our performance variator:

669 Bando Performance drive belt
This is the nearly indestructable Bando brand 669-18-30 for all you guys who keep on breaking belts. These are Aramid cord (like kevlar) for high mileage and reliable use. $29.95

Erlandson 669 drive belt
 Yeah, Gates used to be made in the US, and Bando used to be made in Japan, but both are now made in China. Get this actually American made belt in the popular 669 short case size and see the difference!
729 Bando Performance belt
Aramid corded performance belt for the long case 139qmb engines that have the 12" and larger wheels. These are nearly impossible to break, and give better performance. $34.95

Performance exhaust system
Here is a quality affordable performance exhaust system for your 50cc and larger 139qmb scooter moped. This will give you some more bite and flash that is badly needed. Golden alloy anodized finish on the muffler, and chrome finish on the head pipe. Lowest anywhere at only $114.95 back in stock!

GY6-50 Stainless performance exhaust system.
Looking for a nice exhaust system that performs well too? Glass pack stainless system gives you the top end power and custom sound you want. Comes complete with headpipe and mounting hardware. Fits Chinese four stroke 139qmb 1P39qmb scooters and mopeds.   $119.95
44mm top end kit
Wonders of all wonders. ScrappyDogs now has a complete top end rebuild kit for those VIP, Peace, and other brands that use the 44mm piston instead of the normal 39mm. This can also be used as an affordable 60cc big bore kit (one size down from the 47mm, 72cc kit) affordable, good quality, and in stock! $59.95. Kit includes cylinder, piston, rings, circlips, gaskets, wrist pin as shown.

This kit includes everything you need to upgrade your 50cc 4stroke to 72cc. Many places commonly call this an 80cc kit. Bore diameter is 47mm. This is over a 60% increase in engine size. Expect overall engine performance to improve almost as much. Great deal. Fits most GY6 scooter ATV 139qmb ( QMB139, 139QMA ) engines.  Check your engine number on your case. Works great with your stock head, and bolts right up with no modifications. Super deal, no one is lower than this! $69.95

139qmb performance intake manifold
 Get rid of that junkie old stock rubber manifold and get this all metal one that will last forever! Flows much better than stock. Looks good and quality Hoca construction! Fits all 50cc 4stroke 139qmb type chinese scooter engines. Comes with vacuum ports and new gasket! Hoca is now SSP-G. Same company and quality, new name.
20mm Big Bore performance carburetor
Just put in a big bore, cam, exhaust, or just want a little more performance out of your scoot? This 20mm quality CVK will give you the top end power and speed you need at a price less than the other guy's cheapo standard carb. Save money and get more performance, what more could you ask for? #35 pilot and #85 main jet included.

100cc Big Bore kit
Everything you need to bump your 139qmb engine up to a whopping 83cc. Many places commonly call this a 100cc kit. The bore diameter is a full 50mm, the largest you can go! Get the advantage on everyone else and surpirse the 150's when you keep up with them now. Warning: you may have to register this as a motorcycle now in some states. Comes complete with cylinder, piston, rings, wrist pin, circlips, and gaskets. Capable of using stock head, however performance is fully extracted by using one of our heads listed here. These are priced lower than anyone elses 80cc kits, and some 60cc kits as well. $89.95

4 part video on big bore installation:
23mm CVK Big Bore performance carburetor
High quality CVK performance carburetor that is not only better, but bigger! The venturi on this thing is a whopping 23mm! 5-7mm larger than your stock 139qmb engine. This will still fit into your stock manifold. Got a big bore? Performance cam? Take full advantage of it by putting this CVK pumper carb on it. Comes complete with accelerator pump and dependable electric choke. This is priced about the same as the other guy's standard cheapo carbs! #32 pilot and #88 main jet included.

Big bore head
These are big bore heads for any 47 and 50mm big bore cylinder kits. Good quality casting is machined to fit the larger combustion chambers. $54.95

52MM Big bore kit
Biggest of the big! 52mm big bore kit will give you an actual 85++cc's of torque and power. Guaranteed to make a substantial difference. If you were impressed with our 47mm and 50mm kits, you will be amazed by our 52mm Taiwanese made kits here. These are NOT mundane mainland chinese built. Built to last, and packaged well. Kit comes with cylinder, piston, rings, wrist pin, gaskets and clips. No case modification is necessary for standard cases. This is not for the amateur installer. Compression should not exceed 220psi after break in. This is for the serious avid scooter/atv engine enthusiast only. How do we sell at these ridiculously low prices!?  $99.95
            4 part video on big bore installation:

52mm top end  gaskets
 Replacement base and head gasket set for 52mm big bore kits.
GY6 High Torque Performance starter motors
 Just did that big bore kit? Big valve kit with high compression? Stroker crank? or for the totally performance minded did all of the above and then some? Now your engine won't even crank over with the stock starter? ScrappyDog is the ONLY one that has you covered. Available only from us, Taiwanese quality made high torque, high performance electric starter motors for the gy6-150+ and 139qmb 50cc+ based scooter engines! 50cc has 10 splines. 150cc has 9 splines. Very limited quantity in stock! $89.95
choose your engine

Scrap that limited stock CDI and drop in this unlimited performance CDI with no governer, and an advanced spark timing. This will increase acceleration and top speed by 5-10%, if all else is well. No guarantees on performance parts as this will not improve power if your engine is not running well to begin with. This is plug and play for GY6 scooter atv 50, 125, 150 engines in 152QMI, 152QMJ, 157QMI, 157QMJ, 139QMB 4strokes. If you have this connector and have an AC fired system, it work. See Tech Talk with MO! if your not sure. This is by far the lowest price unit on the market. $19.95

Installation video here: http://www.youtube.com/watch?v=LcE7fOLfnys
GY6 Racing gold CDI
Here it is for those of you that must have the best. Racing CDI for GY6 based engines in 139qmb and 157qmj and also the 125cc version also. Works with any AC ignition systems with this type plug on it. This is similar to our orange performance CDI, but a more agressive ignition advance curve. Recommended for the serious build. $24.95

This is the hard to find performance CDI for your DC fired system. These are found on the Kymco Agility 50, Diamo Velocity, Vento Triton, SYM VS 125, VMOTO 125cc Monaco, Schwinn, Tomos Nitro 50, Eton sport 50, SYM sport 50, Baja SC50 Sun City, and other  Chinese, Korean, and Taiwanese scooters. These also include engine type 139QMA. You will have a 3 phase type generator and regulator/rectifier. Feel free to contact us to ensure proper fit, because we're sure the price fits at just $29.95
Gave my Tomos nitro 50cc 13mph extra, very happy AAAA++++
These may not work properly with Eton Beamer or Sym Jet Euro 50

Bolt Box Fully Programmable Digital ignition advance CDI

Plainly said, you are not getting the most power out of your engine unless you have full control of your ignition timing advance. There is no other product on the market like this. The Bolt Box allows you to configure your timing in one degree increments up to 60 degrees advance in 1k rpm segments in real time and without a computer with the intuitive menu buttons on the face. This also allows you to set you rev limit to any speed and is capable of 19,900 rpm's. You can also switch between two ignition maps with the flick of a switch mounted on your handlebar. While running, this unit also functions as a digital tachometer! The Bolt Box is fully compatible with the AC ignition stators found on most scooters today. With the addition of our Inverter, you can go fully DC and eliminate the stator completely! Nonvolatile EEPROM configuration memory keeps your settings internally for life even without power. Made in Europe with an American brand microprocessor and ultra fast capacitor, this is not for the amateur, but for those that are or are going to be doing all the big modifications and want to ensure they are getting the full potential and bang for the buck from their engine, and this does it. This requires some simple wiring and an elementary understanding of electrics, but includes full instructions and schematics. Works with ALL scooter brands from any country and also works with any single cylinder motorcycle, 2T or 4T. At $179.95 the Bolt Box can't be beat. Limited quantities in stock, so get them while you can!
Bolt Box Inverter
This is the DC to AC inverter you need for the Bolt Box listed above to run in full DC mode. This is the preferable setup for clean and reliable power delivery and eliminates your erratic AC ignition stator. Sold for only $49.95 and made in Europe, this is fully sealed and built to last.
High energy ignition coil boosts that weak spark into a real shocker. This will improve starting, acceleration, and fuel mileage. This is plug and play for GY6 scooter atv 50, 125, 150 engines in 152QMI, 152QMJ, 157QMI, 157QMJ, 139QMB, 172MM, CF250, and all other 4strokes. As on all performance parts, no guarantee, as these parts will not fix a problem you may have elsewhere. Fits all Chinese 4stroke engines as well as your budget. $19.95

Red hot high energy GY6 ignition coil
This GY6 performance ignition coil is similar to our orange coil, but hotter and more powerful! These fit all the fourstroke scooter/atv engines like the 139qmb, 152qmi, 157qmj, 172mm, 50cc, 125cc, 150cc, 250cc. Simple one bolt installation. Tank, Jonway, Honda Helix, NST, JMstar, etc. Now actually in stock and made in Taiwan!!! $29.95
CR7 Iridium Spark Plugs
Longer life, more stable spark energy are just some of the benefits of our Iridium spark plugs. Get them here cheaper than anywhere else as always. $9.95
High performance air filters
High flow performance air filter, clamps right onto your carburetor. Small profile to ensure tight clearance fits. Some 150's have a suspension cross member that interferes with filter installation. Not this one. Fits Tank, Sunl, Roketa, TNG, TGB, JMstar, Jonway. Just about any scooter, atv, buggy, dirt bike, etc. In our efforts to make ordering easier, and cheaper for our customers, we now have this available as a kit combined with a main jet in various sizes. 38mm for the 50cc carb.  $9.95
choose your kit

Chrome Performance Air Filters
 Universal fit reusable filter with chrome end caps.
Sold each - order one filter per carburetor.
It is recommended to measure your carburetor air filter mounting flange prior to installation.
By popular demand, we are offering these K&N style pod filters in addition to our Uni foam pod filters sold above. $11.95
choose your size option
Splash proof performance air filter
 Live in a wet and rainy part of the world and have issues with your rear wheel flinging water into your performance air filter? These have a protective plastic covering that helps prevent water flame out. Comes in 38mm for 50cc and 42mm for 150cc. Price for one is $14.95
choose your size
139QMB 50cc carburetor main jet
Main carburetor jet for the high speed circuit. Get it replaced here cheap. These come in three different sizes: standard, #75, #80, #85, the popular #88, and the gas guzzling #95 75 and 80 are good for exhaust upgrades, etc, but still stock air box. 85 and 88 are for air filter upgrades. 95 for major stuff. Cheap at only $3.95
choose your size

Performance Pre-filter
Want to preserve your new performance air filter and engine? This slip on pre-filter fits over our sock filters and prevents the larger particles and other debris from ever getting to your main filter, allowing it to last longer and filter more efficiently. Super cheap! $2.95 (may come in black or orange)

Positive Crankcase Ventilator
Have, or are you removing your airbox?Is your scoot blowing oil? Have you run dry and don't know why? The reason may be that excessive pressure is being built up in your crankcase, which blows seals and/or pumps all your oil out the vent. This nifty device actually creates a vacuum within your engine by only allowing air out, and not back in. Made in the USA all steel construcion easily attaches to your vent line, which should be place above your engine as far as possible, and installed on the barbed nipple end. Threaded end is left open, or attached to a filter if you wish. This is a must if your running your scoot full throttle alot. New improved model. Cheapest performance fix anywhere at only $9.95
Crankcase vent/oil catch can
Crankcase vent and oil catch can solves all your venting problems. Oftentimes, scooters and ATV's are run full throttle for extended periods under heavy load. This causes alot of pressure to be built up in the crankcase, which results in a heavy oil vapor escaping out the vent, or anywhere else it can find, like through your seals. This can blow enough oil out that you could run out of oil before you think to check the level. Adds another vent outlet by replacing your oil dipstick. Attaches to your existing line also. We highly recommend adding the PCV to the outlet of this unit also. One line attaches to the existing vent, the other to the new dipstick, the other to atmosphere via PCV valve. Easy installation with all hardware included. Works with any engine. Color may vary. $29.95
Installation video here:  https://www.youtube.com/watch?v=5ki1gANVO14
***replaced by the JET catch can below***
JET oil catch can
 More affordable crankcase vent/oil catch can, all chrome steel JET oil catch can like above, but smaller. Includes canister with mounting bracket, oil line, and new vent that replaces your oil dipstick. Super cool unit for an unbeatable price.
GY6 retrofit oil cooler kit
 We've been looking for a very long time to get a retrofit oil cooler kit that isn't so darn expensive for the gy6-50 139qmb and the gy6-150, and here it is! This unit simply replaces your oil screen on the bottom of your scooter/atv engine and circulates oil through the radiator to keep your oil nice and cool. This is a must for any performance enthusiast who wants to keep their investment they have made in building a performance engine. Comes with radiator, lines, adapters, banjo fittings, clamps, mounts and all accessories. There is enough line to mount this pretty much anywhere. 
Get this, it's only $89.95
Hoca Oil Pressure Release kit
 Hoca oil pressure release kit for gy6 based 4stroke engines and others that use a similar size dipstick. This kit helps reduce the negative pressure build up that can harm your engine.                
  • $37.95

Turbo cooling fan
 Super duper cooling fan. Why spend all that money on a high performance engine build just to have it burn up because you didn't upgrade the cooling system. On air cooled scooters, the air is forced by fan. This throws more air. More air means cooler and longer lasting engine. Get with the program at only $14.95
Performance Torque Spring
Scooter bogging down going uphill? Why put up with it? This spring will get you moving up those hills again $14.95. Color may come in black or uncolored.
choose your spring rate

Performance Clutch Springs
Get that little 50cc fourstroke ahead of the traffic at the stoplight with these cool  clutch springs at only $9.95 Color may come in black or uncolored.
choose your spring rate

High performance clutch
Now that you've got the power, you better make sure you can get it to the ground now. Super sticky high temp clutch pads and rigid actuation arms make this the right part for the job. $39.95

Performance clutch bell
Performance ventilated clutch bell. Perfect match for our performance clutch. This thing just looks cool, as well as being cooler. $29.95

Performance torque sheave
This is an aggressively angled cam torque sliding sheave for you real performance nuts out there that must get every edge possible. $39.95 Popular item back in stock while supplies last. now comes with both sides of sheave completely assembled for the same great price!

HOCA Performance clutch/pulley/bell
 Oh now this is super sweet! Complete rear clutch pulley and bell for the performance enthusiast that wants the best, but isn't the best mechanic and doesn't want to mess with opening up the rear sheave. Comes with all the performance goodies like yellow torque spring, blue launch clutch springs, aluminum heat dissipating ventilated outer bell housing, fully adjustable, etc. Taiwan quality of course for only $117.95
SDS Performance clutch/pulley/bell
 Hey, not everyone can afford the taiwanese HOCA clutch/pulley assembly above, and not everyone is able to, or have the time or tools to install torque and clutch springs themselves, so ScrappyDog has developed these complete assemblies ready to install with red big torque spring and red clutch launch springs. Includes the performance sheave and ventilated bell for only $79.95. This is the most common setup and is in stock and ready to ship...for now!
139qmb Chrome belt cover (long case)
 Where do we find all this stuff!? We'll never tell...Chrome performance custom belt case for those of you that have it all, but never have enough, or just want some bling to your scoot! Fully ventilated and chromed out. You can actually see your clutch spinning around in the open air!
139qmb Chrome belt cover (short case)
 Same cool chromed and ventilated belt cover as above, but for the more common short case engine which has 10" rear wheels.
139qmb Chrome extra long belt cover
 You won't find this anywhere, for any price. This is the extra long, yes, extra long chrome belt cover found on some certain Zoomer/Ruckus style chinese scooters like the IceBear Maddog! Get 'em while you can.
Billet aluminum dipstick
 Solid billet aluminum dipstick made from solid stock, and polished, with o-ring for GY6 150 and 50. Now this is frickin cool stuff.
Performance A9 Camshaft
A9 is the sport high end camshaft for your 139qmb 49cc fourstroke scooter/atv. This will also improve your big bore performance. This will give you the top end speed potential that you need. Same Taiwanese quality parts as all our performance parts here. Tomax Racing Taiwan. $39.95

139QMB GY6 50cc scooter moped big bore kit rings 47mm and 50mm

This is a brand new quality Taiwanese ring set for our 47mm and 50mm big bore kit in your 50cc scooter/atv/buggy chinese engine found in many brands like Tank, Roketa, JMstar, Jonway, Vento, TNG, VIP etc 
Remember, these are better than original and will last and perform better than original. It's a good idea even to put these in new kits.
These are easy to break, not to mention irriitating when you can't find them to replace them. Get it fast with ScrappyDogs!

Choose your size

139QMB GY6 50cc scooter moped big bore kit gasket set

This is a brand new quality gasket set for our 47 and 50mm big bore kit in your 50cc scooter/atv/buggy chinese engine found in many brands like Tank, Roketa, JMstar, Jonway, Vento, TNG, VIP etc 
Be sure and replace these gaskets whenever you take apart your engine. Get 'em fast with ScrappyDogs

Choose your size

GY6 service and repair manual
Here is a CD with tens of megabytes of useful service information for your GY6, 139QMB 139QMA Chinese scooter/atv engine and chassis. This includes some wiring diagrams, the scooter book, some chassis technical info, SYM and Kymco books. Comes on a CD-R ready for you to view or print. $14.95

139qmb performance glide keys
 Glide keys for performance or standard variators. Decreases friction in variator function and extends glide life by many time to boot! Genuine Dr Pulley brand. Set of 3 for only $4.99
Big bore top end assembly
Complete top end assembly in two sizes available, both 47mm and 50mm. This includes big bore cylinder, piston, rings, wrist pin, circlips, gaskets, and a fully assembled head. Combined shipping saves you big. $119.95
choose your size

Pre-jetted carb/performance air filter
Don't have time or the skill to jet your carb? We now have a pre-jetted carb for your 50cc scooter. Comes complete with 18mm CVK standard carb, 38mm performance high flow air filter, and the most common #88 main jet already installed for you. This jet setting has proven to work best with these filters, in conjuction with other small performance upgrades like CDI's and coils. $59.95 

Stage III Performance package kit
Don't want to have to spend alot of time figuring out what you need? Get this pre-designed package for your 50cc scoot/ATV. Comes with everything you need for a nice big boost in power. Big bore cylinder, piston, rings, gaskets, clips, wrist pin, performance air filter, 7g copper core rollers, iridium plug, fuel filter, and #85 jet. Save big on package pricing and combined shipping. Ships by priority mail. Delivery within 2-3 days in the US!
 Comes in 80 and 100cc based kits As low as $99.95

choose big bore size

Stage IV performance package kit
Just gotta have the best? This is a complete engine performance package designed to boost total power up considerably. Kit includes 47mm big bore setup, performance stainless exhaust system, iridium plug, big valve racing head, 125cc intake boot, 24mm RunTong carburetor. Package price and combined shipping save you even more.  Delivered to your door in 2-3 days. $329.95 to get some burnouts! Here is a posted testimonial:

Carburetor pilot idle jets (upgraded and standard)
This is that little jet that causes so much trouble. If your bike is stumbling off idle, won't run when warmed up, or has been sitting for a long time and won't stay running, replace this jet and cure the problem. We also have these in upgraded sizes, like #38 and #40 (stock is #35). The larger size makes starting easier, and off idle power increased. Easy swap and cheap fix. #40 is for the real hard starters. $4.95  
choose your size

Performance transmission gear set
Scoot revving to the max, and just not going any faster? Seem like your engine is just running too high? Need that extra top speed boost? Performance gear set gets your going. Gear ratio is a 49/17T, which is 2.88. Potential of up to 10mph top speed increase! Taiwanese quality, at a Chinese price. $39.95
Back in stock! But for how long? Simple press fit can be done by anyone with simple tools and skill. This gear ratio is the best compromise between take off acceleration and top speed. Other kits make you bog coming off the line.

            Video on how to install gear sets: https://www.youtube.com/watch?v=KPkUeLqDCWo
Big bore performance gasket kit
Compete gasket kit for your big bore 80 and 100cc scoots. Has everything you need in one nifty kit. $19.95 

GY6-80 engine assembly
Complete big bore engine assembly for your long case 139qmb gy6 based scoot! Bolt right into your existing mounting of your 50cc fourstroke scooter. Yes, this is complete with everything in the engine and CVT, and will fit short case applications also. Forget all the hassle and expense of installing a big bore kit, just get it done right and easy here.  These have the long dual shock shaft installed. We also sell the short shaft if you need it, or re-use your original one. Easy, quick upgrade swap.  $374.95
GY6 performance rear shock
Gas charged, remote reservoir racing rear shock. Fully anodized aluminum with heavy duty springs greatly improves road handling and bottoming out. Works and lasts longer than original by light years! Sold as singles for rock bottom price at this quality level. $99.95

Forsa performance shock
 Performance shock for all you cheap skates that don't want or can't afford the real deal gas charged shock sold above :) JK, no but really. This is a lighter weight, slightly shorter (280mm), without remote resevoir, and not quite as good looking or long lasting. Spring rate is good for a 50cc with eyelet on one end and clevis on the other.
GY6-100 complete engine!!!
 GY6-100 engine with 50mm bore is now available in long case, long shaft model. Generally a beefier HD version of the standard 139qmb, but can use standard replacement and performance parts. This could be used in a short case installation, but is a couple of inches longer.  Get your slow scooter into the fast now!  $399.95 ***backordered. Click to order the gy6-80 or 50cc engine with big bore kit included***
Performance Lithium battery
 Lithium ion Polymer technology
All components are designed, manufactured, assembled and packed in one location assuring high quality and consistency.
Extremely lightweight, 50 to 70% lighter than standard batteries.
Built in LED test gauge on top.
Increased cranking amps over lead acid batteries.
Fast recharge, can be brought up to 90% charge within 6 minutes.
Comes fully charged and hold a charge without maintenance for up to a year!
Easily 6 to 12 times more cycle life compared to lead acid batteries.
Long shelf life, up to 1 year before requiring recharging.
Can be mounted in any position.
No hazardous acid or heavy metals, non-explosive and non-combustable.
No shipping restrictions.
More precise fitments compared to other brands of lithium batteries.            
Nuff said. Lead acid and AGM batteries are obsolete. Make the up front investment in these lithium batteries and it will save you money in the long run.
We sell two sizes for the 4amp and 7amp size frames found commonly in chinese scooters.
Measurements are: 4 7/16 x 2 3/4 x 3 3/8 and 6 x 3 7/16 x 3 11/16
Remember, lithium batteries are more compact and packe a bigger punch than standard batteries, so a smaller battery will perform much better than a comparable battery the same size.
Note: these are much higher rating than standard acid batteries. 4amp battery actually cranks out a full 150 CCA's for those hard starting small frame 50cc scooters, this, along with our heavy duty starter is the fix.
$98.95 for either 4amp or 7amp size
choose your size
Hoca Big Valve head
 Machine made big valve head works great with our 47mm and 50mm big bore kits to give you maximum horsepower when coupled with performance exhaust, cdi, etc.  Fits 139qmb gy6 based 4stroke scooters.

  • Intake Valve Diameter: 21.5mm
  • Intake Port Diameter: 24mm
  • Exhaust Valve Diameter: 18.9mm
  • Exhaust Port Diameter: 22mm
  • Valve Length: 62.3mm (compatible with 64mm Short Valve Style Heads) 
  • Does not come with camshaft, please see Related Items
  • $129.95
  • Hoca 52mm big bore kit

    img-qind.JPGHoca 50cc QMB139 4-stroke 52mm, Racing Big Bore Cylinder Set. Kit includes cylinder, piston, rings, piston pin, cir clips, head gasket, and base gasket.

    When you use this Hoca 52mm Big Bore Cylinder Set in conjunction with our 44mm Stroker Crankshaft (See Related Items) you will increase your total displacement to 93.4cc, almost doubling your original displacement!!!

    High Flow/High Capacity fuel filter
     This is the biggest and baddest fuel filter you can get for your hot rod scooter or motorcycle or atv/buggy. Don't compromise on this. 8 square inches of polymerized paper filter area suitable for gasoline or gasahol. Gravity flow rate of 7.6 gallons per hour! These are super good quality and will likely be your last filter. Look at this pic that shows the performance filter next to a standard filter. (one filter per purchase...don't get confused)
    10 piece 139qmb carb tuning kit
     QMB139 CVK Main Jet Kit for 50cc 4-stroke QMB139 carburetors includes a size range from #72 - #110.

    50 piece 139qmb shop jet kit
     QMB139 CVK Main Jet Kit for 50cc 4-stroke QMB139 carburetors includes a size range from #72 - #110. 50 piece set.
    Upcoming Schedule of Events

    Date Time Event
    7/1/2005 5:00pm Company Picnic at Shallowford Farms
    7/11/2005 2:00pm Walk-a-thon for Charity
    Website Builder