Chinese Scooter 49cc to 80cc Big Bore Kit QMB139

If you are looking to get a little more power out of your scooter, this is by far the best bang for your buck! This will convert your 49cc engine to an 80cc engine. The take off speed will be twice as good and the top speed will increase a bit. This will solve the dreaded loss of speed going up hills. Your fresh 80cc big bore kit will now have the muscle to push you up hills and help with the take off speed from a dead stop. No more people honking at you for going slow as a snail... you get the picture! This kit is what you need! At Rolling Wrench we use nothing but the best. We did a lot of testing with the eBay/amazon kits, they failed over time almost every time. This 80cc kit is the ticket. These are fairly simple to install especially since we put together a "how to install a big bore kit" video. Any questions just ask!

NOTE: This kit will reuse your stock head. Piston rings come pre installed for an easy install.

We recommend a performance ca, but its not totally  needed: CLICK HERE

ADD THIS CARBURETOR TO REALLY BRING IT TO LIFE! CLICK HERE

We have a no-return or exchange policy on all performance parts. Upgrading to a performance part may degrade the original reliability of your scooter.  

This 80cc big bore kit will fit the models below:

- QMB139 / 139QMB / GY6 50 (4-stoke) engines.

Want to know exactly how to install this kit? We have a step by step install video click here.

GY6 torque settings click here.

How do I know if this kit will fit my engine? Watch the video below:

To purchase the 45 min. install video click here.