100cc Big Bore 50mm Cylinder Rebuild Kit for GY6 50cc ATV Moped Scooter 139QMA 139QMB

My scooter only went 30 mph befor now it does 55 mph and does wheelies you can’t beat it for the price and it’s been running fine for 1,000 miles now

I needed this for a Dongfang SST DF50 I’m dual-sporterizing. Good quality on the kit package (not fancy) but it’s how parts fit and work, it installed well, everything lined up and certainly makes a difference on the 49cc. It’s very worth your while to upgrade. You’ll also need a bigger carb to get the full effect and probably new weights in the variator.

The piston rings were not the right size at, they were to small

I bought this kit and it shipped to my house on time. At first glance, it appeared everything was included. However, upon further inspection I found that the piston rings were not even close to the right size. They were very small and will not work. Now having to spend another $25 to get the proper rings delivered. Very disappointed.

I liked that it came kind of quick I just liked and disliked that after two days of riding it the piston rings burnt out burnt up which messed up my valvesI’ve done this to another company and now big bore kit still running like a champ so that that was pretty much a waste of time and money and I hate running bad reviews

Install wasn't difficult and the kit was good

I liked this part for my 50cc taotao. It went together perfect works grate picked up a little speed better pulling up the hills now also.I like it I'm very happy.

WORKS GOOD I CAN START IT WITH KICK START NOW AND IT WILL START WITH OUT TOUCHING THROTTLE