YZ250 Big Bore Kit Power valve Complete Motor Engine Rebuild Kit Top Bottom End

72mm big bore cylinder***
Wiseco or Wossner 72mm big bore forged performance piston
Nitrite coated piston rings
Chrome wristpin
Circlips
Big bore cylinder head
Powervalve machined for 72mm bore
Talon HD replacement crank with rod assembled
SKF HD crank bearings
Transmission bearings
Shift cam bearings
Water pump bearing
Wristpin bearing
TITANIUM cylinder stud kit with 12 point flange nuts
TITANIUM cylinder head stud kit with 12 point flange nuts
Complete gasket kit
Seal kit
Compatible with all 2003+ Yamaha YZ250 and YZ250X two stroke models
1 year warranty*
***Powervalve and cylinder head modification required for ALL 72mm big bore cylinders

*Warranty: We stand behind all parts we sell 100%.  Everything we sell has been tested hundreds if not thousands of times and when installed and tuned correctly they work over 99% of the time.  Part failures happen, but it is rare that it is not due to being installed incorrectly.  If after installation there is an issue contact us for a warranty return.  This product is NOT DIY.  Over 99% of people in the world are not qualified to build an engine, and it is the responsibility of the person assembling and tuning the engine to make sure everything works correctly.  It requires special tools and has to be done 100% correct.  Many parts must be measured down to .01”.  We ALWAYS STRONGLY recommend parts be installed by a qualified, experienced mechanic.  Warranty does not cover failure that is a result of improper installation, tuning, break in, or misuse.   STUD WARRANTY: If for any reason a stud fails during use, not installation, we will send a completely new stud kit.  No other parts or any labor are included, and it can not be converted to a refund or discount on any order.  Studs must be returned to us for inspection first.  ALPHA CUB WARRANTY: If your Alpha Cub cylinder fails for any reason not related to installation, tuning, break in, or misuse we will fix the cylinder free of charge.  If it can not be fixed we will supply you with a new one

Compatibility