GOOFIT 50mm Big Bore Cylinder Rebuild Kit Parts Bore Upgrade Replacement For GY6 50cc 100cc 139qmb Racing Scooter

I bought this bore kit for my wife's 50cc as her scooter piston had gone and thought it would be a cheap up grade and was surprised with how much performance it gained on a stock engine it went from 30mph stock to 45mph gps speed with out any other mods and left my 50cc behind I was so impressed I bought a second one and fitted it to mine I'm running 6.5 roller weights and a performance variator and getting 55mph the only down side to this kit are the 9 gram rollers that are included are too heavy and a shame it does not come with 6 or 6.5 gram rollers but very satisfied

Arrived very quickly. Had an issue with a sticky valve but goofit sent out a replacement very fast. Bike pulls away a lot faster now and accelerates up hills 😁 you will have to change the jets in the carburetor or just buy a bigger carb which aren't expensive. Very happy overall as I'd never tried anything like this. 😁

good quality product.not had engine running yet because the carb jet was missing from the kit.

good value for money pritty easy to install very good item

Delivered fast. The kit is immaculate. Awaiting to get it fitted. Noob to this mid scene so not sure what carb or jets to get

Valves sticking open so bike will not run .could not detect this fault until fitted

Very good condition works perfectly much better performance of the scooter

Everything is great but no carb jet included ! Which is clearly advertised on the pictures as being included