(photo shows old, cast piston)

290cc BORE KIT

#00367

$299.00

80mm Piston, Variable Compression,

  Select from the following:

●  9:1 with stock stroke, 10:1 with +9.5mm Stroker

● 10:1 with stock stroke, 11:1 with +9.5mm Stroker

● 11:1 with stock stroke, 12:1 with +9.5mm Stroker

● 12:1 with stock stroke, 13.5:1 with +9.5mm Stroker

● 13:1 with stock stroke, 15:1 with +9.5mm Stroker

Compression ratios are estimates, based on standard cylinder and head configurations. Modifications or slight production anomalies can significantly increase or decrease compression ratio.

AHRMA Legal in 250 Class. Great overall power increase, especially with higher compression ratios. Kickstarting not recommended with CR higher than 11.5:1.

INCLUDES: Forged piston, pin, rings, circlips, headgasket.

REQUIRES: Boring, rejetting.

Fuel requirements: Up to 10:1 Compression = Premium Pump fuel.  11:1 to 12:1 = 108+ octane.  Over 12:1 = 112+ octane or Alcohol. 

+9.5mm STROKER

#16017RA

$550.00

+9.5mm Stroke

340cc with 80mm Piston

Excellent torque and great midrange power increases.

INCLUDES: New rod, pin, and needle assembly. Work done on your crank. Additional cost for other parts (main bearings, timing sprocket), if needed.

REQUIRES: Send in your crank for modification. Download our Stroker Booklet for details. Non-Powroll pistons may need skirt modification.