+4.2mm Stroker Crankshaft for the 04-05 Honda TRX450R.

This crankshaft is an OEM crankshaft that has been stroked +4.2mm. This crankshaft uses an OEM quality Crank Pin and Rod Bearing. It also uses a Custom Stock Length Carrillo Rod with a 19mm top bushing. This crankshaft is designed to be used with the 06+ TRX450R or 02-08 CRF450R piston. WILL NOT WORK WITH A 04-05 TRX450R PISTON.

This Crankshaft is designed and tested to be used in High HP applications. Can be used to build a great dunning / drag racing engine.

Crankshaft is trued and welded as well.

This crankshaft requires no crankcase machining for installation.

Engine Setup Note:
-Uses 06+ TRX450R or 02-08 CRF450R Pistons, Will Not Work with 04-05 TRX450R Pistons
-With Stock Combustion Chamber (Approx. 38.5 cc's), you will have lose approx. 0.5 a Point of Compression compared to the Rated Compression of the Piston chosen (ex. CP #M2011 12.5:1 97mm 02-08 CRF450R Piston will be 12:1 Compression with this stroker setup and Stock Combustion Chamber)
-*Can Mill the Cylinder Head Deck to decrease the Combustion Chamber Volume and increase compression ratio of the engine. We have tested up to 0.060" decked off of the cylinder head (Combustion Chamber is approx. 30.5 cc's with a typical unshrouded ported combustion chamber). With a 0.060" Decked Cylinder Head, you will see a significate increase in compression ratio compared to the rated compression ratio of the piston. Compression Ratio will be up approx. 1.8 Points of Compression vs Rated Compression of the Piston chosen (ex. CP #M2011 12.5:1 97mm 02-08 CRF450R Piston will be approx. 14.3:1 Compression with this Stroker Setup and a -0.060" Milled Cylinder Head).* Less can be milled from the cylinder head if less compression ratio increase is desired.

If you are looking for a complete kit, we offer several engine kits that use this crankshaft. Check the complete kits out below.

97mm 511cc big bore stroker kit

99mm 531cc big bore stroker kit

103mm 575cc big bore stroker kit

*If you Mill the Cylinder Head, a Manual Cam Chain Tensioner is required otherwise accelerated Cam Chain Wear / Streching will occur. A Properly Adjusted Manual Cam Chain Tensioner will return the Cam Chain Life back to STD operating conditions. Milled Cylinder Head Compression Ratio's are just approximate ratings, you should CC the Piston and Cylinder Head and calculate your compression ratio to verify exactly what Compression Ratio your engine will be at. All Clearances must be checked if you mill the cylinder head.