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Fan - Cooling QMB139
Fan - Cooling QMB139
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49cc 50cc 150cc 250cc Motorscooters
49cc 4-st to 100cc Big Bore engine upgrade kit
 MSRP: $235.00
 Our Price: $195.00
 You Save: $40.00
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The engine upgrade kit will virtually double your horsepower taking the engine from 49cc's to 100cc's. The effect will be additional 5-20 mph and more power. The kit includes everything needed including a new cylinder head, wider piston, rings, fuel and exhaust valves and valve springs and the necessary gaskets to do this upgrade using your existing head assembly. Installation of the kit does require some special tools and small motor experience, we strongly recommend someone who has small engine experience do the work.

The QMB139 49/50cc engine is used on virtually all 49cc, 4-stroke imported scooters regardless of the Brand/model, body type, name or manufacturer. Baja SC50, Strada RX 50, Jalon JL50QT-21, Falcon and JL50QT-15, JL50QT-16,Strada RX 50, Jalon JL50QT-21 , JL50QT-15, JL50QT-16, JL50QT-18, Pantera Freedom, Fusion and Retro, Verucci 4s,10A,10D,RetroSport, Avispa, Sports Edition, 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, Taishan Sport Zhong Hu 50cc 4t, most Jonway, Tank, Lance Powersports and many more.....

Available in 64mm and 69mm valve sizes.  Select the correct model below


100cc Big Bore Kit for QMB139 50cc Engines



Available in 64mm and 69mm valve sizes.  Select the correct model below

For Your 49cc 4-st to 100cc Big Bore engine upgrade kit
Available Options:
Valve Size:
DISCLAIMER: we make this article and many of these parts available to you because many of our customers have requested them. Using them requires knowledge of how a CVT transmission works. Since small modifications cause big changes and many variables are involved; we will not offer any technical assistance for parts listed in this section. If you are not sure that you can install and adjust your transmission for maximum performance, do not purchase these parts. Thank you for your understanding. Please note: high performance parts carry no warranty period! All high performance parts are for off-road use only and are not intended for legal street use. Use of any of these parts on public highways may be illegal. Installation of any of these parts may void your factory warranty. In addition, the high performance parts may produce more power than the bike was originally intended for. In other words, use at your own risk.!!!! We make no warranty to products distributed, expressed or implied, including and without limitation any warranties or merchantability and fitness for a particular purpose. We will pass on all warranties made by the manufacturer (if any) who has the sole responsibility for performing such warranties. The manufacturer shall be solely responsible for any damage to person or property arising from the design, manufacture and testing of its products and ScootsUSA accepts no liability for such damages and shall not be liable for indirect or consequential damages. Riding a motor scooter can be dangerous. Riding a really fast motor scooter can be really dangerous. Always wear a helmet. Have fun!

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ScootsUSA DOES NOT SELL MINIBIKES OR POCKETBIKES. These Motor Scooters are Full Size and can be compared to the well known Vespa.
www.scootsusa.com - For the best gas motor scooters buy a gas motor scooter / moped.



Sales Tax is collected for VA and FL orders only. We ship to the 48 contiguous United States only. No shipments to AK, HW, or Canada. Please note that most motor scooters arrive 99% assembled. Some require only attaching the mirrors and hooking up the battery. With all motor scooters we highly recommend the use of a mechanic to perform safety and mechanical checks BEFORE you ride. Many motor scooters selling under $1000, typically require assembly of the front wheel, front fairing, and handle bar items, previously assembled and tested then unattached from the bike before shipment. This assembly typically takes an hour or so to be ready for the road. Other adjustments and minor mechanical work may need to be performed by you or your mechanic during the life of your motor scooter. Properly maintained your motor scooter will provide years and years of service. Please remember, it is solely your responsibility to check and comply with the rules and laws within your state. You are solely responsible for determining the legality of your motor scooter or moped in your state. ScootsUSA will not issue any refunds based on claims of unsatisfactory legal status. ScootsUSA has provided links to state DMVs on this site. ScootsUSA assumes absolutely no liability whatsoever for use of motor scooters. Please make your buying choice carefully. We want you to be very happy and confident with your purchase, but we have a strict no returns no refunds policy. Review the terms and conditions and FAQs to help you make an informed buying decision.

*The definition of "street legal" varies among states.

ScootsUSA is an authorized sales representative of Verucci Motor Cycles. MSOs and invoices from the respective manufacturers will bear their name.

At ScootsUSA we sell the best motor scooters and the best mopeds combining price and quality. ScootsUSA sells accessories and offer an inventory of Motor Scooters and Moped parts, entirely online. Whether you are looking for an off-road dirt bike, go-kart or motor scooter accessories we have all of this and more, including a full range of ATV's and dirt bikes. If you are looking for moped performance, parts or an affordable motor scooter then ScootsUSA can not only assist you with the purchase of new scooters, but we also provide you with an exclusive "Customer Only Area" where you would find full information on maintenance of your motor scooter. We are your number one motor scooter store in the USA. If you are in need of an alarm system, new battery, halogen head light bulbs, carburetor or drive belt, fan or fuel pump (+ performance parts) for your scooter, everything is at ScootsUSA - for the very best motor scooters and the very best mopeds, at affordable prices.
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