GY6 171cc Scooter Big Bore Kits (FITS QMJ157)
. If you are looking for the best bang for your buck in performance CLICK HERE. The Rolling Wrench kit is the ticket! We have spent years testing and selling other kits. Some things we liked and others we didn't. We pieced this kit together with the best of the best materials (rings, gaskets, springs, and metals) This 171cc kit is a no case boring big bore kit unlike some others on the market. Its the largest big bore kit you can go on the GY6 A motor (Chinese GY6 qmj157). Our 61mm kit is a drop in kit. Others on the market are not and will require engine case boring. Like they say “There is no replacement for displacement“. Another cool thing is the piston ring end gaps have been set and installed into the cylinder. This eliminates a ton of work and liability on your end. Easy Peezy! For the money this kit flat out rocks! We even have a install video! We would recommend adding a performance cam shaft and big valve head to the kit for max power! Annnnd if you want to take it one step further you can add the forged piston option for better strength and durability. We even have the option of adding the performance big valve head and performance cam shaft! You can even add a performance carburetor, but it’s not a necessity. (Click here)
You may find other kits for half the price online but note: they are made in China. This kit is made in Taiwan and there is a HUGE difference in quality.
THIS KIT HAS 54MM STUD SPACING (GY6 A)
ADD A WIDE BAND O2 SENSOR KIT TO MAKE TUNING A BREEZE! CLICK HERETHERE ARE NO RETURNS ON PERFORMANCE PARTS.
FREE INSTALL VIDEO BELOW: