51mm stroker crank

  • Sale
  • Regular price $149.00
Shipping calculated at checkout.


  • 108cc when combined with the 88cc kit
  • The ATC70 had two different crankshafts. The 78-80 has a shorter crank than the 81-85. please check your engine number and choose the correct year before purchasing.
  • If you already have a TB 88cc kit you will need to purchase the new stroker piston/rings @ $59.00. 
  • When purchasing the entire big bore/stroker kit together we will provide the correct piston
  • The 6volt high volume oil pump is required with this crank. You will also need to upgrade your clutch.
  • Includes center case gasket.
  • Installation of this part requires the engine cases to be split. Unless you are very experienced at working on these engines, 
    we recommend having a professional technician do the work.
  • All performance parts have no warranty.