Big Bore Kits
Send us your cylinder and head (two stroke cylinders only) along with the power valves, we will bore, sleeve or Re-Nikasil your cylinder to the new larger size. Your power valves will be modified if needed to function properly with the larger bore size. Some models will have the cylinder head re-chambered for the proper volume and compression ratio. Our big bore kits include a high performance piston with piston rings, piston
pin and circlips. New top end gaskets are included for most models.
BIG BORE KITS ARE AVAILABLE FOR:
2 STROKE - 4 STROKE - DIRT BIKE STREET BIKE - ATV - MOTORCYCLE
Kustom Kraft Performance Big Bore Kit
Yamaha Motorcycle and ATV Kits
AMA competition bulletin:
amateur motocross class rules changes governing big bore kits.
See Full-Size Image Of KLX250 Dyno Test Here
2 Stroke-4 Stroke-Dirt Bike-Street Bike
A Kustom Kraft Big Bore kit is the least expensive way to increase overall performance. There is no substitute for displacement. An increase in displacement is directly related to torque. Unlike other engine modifications there is no sacrifice in power on one end on the power band for the sake of the other end. The big bore kit will increase both torque and horse power over a broad range. Our reliable bore kits offer huge increases in torque for great low end and increased power through out the entire power band. No other modification can deliver the performance like a genuine Kustom Kraft
Big Bore Kit.