Duncan Racing's Complete 740cc Engine Performance Package for the Yamaha Raptor

Includes:
Fat Boy 4 Complete Exhaust System, 740cc Forged JE Piston Kit (12-1 compression), Big Bore Sleeve (installed & bored), head gasket, Hard faced Camshaft, HD Valve Springs w/Titanium Retainers, Shortened Bronze Guides, DR Head Porting (with guides out) and Valve Seat Cut, Instructions, DR Tech Support. Cylinder Head is returned assembled and ready to install.


*Center case machining is required to install the 740cc Kit.
**DRI charges $125.00 to machine center cases for 740cc sleeve if engine is disassembled and cases are sent to DRI.
***DRI also offers complete engine teardown and reassembly. Call for details

Kit Options:
Camshafts Options- X3H Grind "All Around" Power Gain. Lift .452”/.429”, Duration 276°/274°
X14H Grind "Full Race/Top End" Power Gain. Lift .452”/.412”, Duration 292°/294°

DRI uses hardfaced camshafts only for the Raptor. A hardfaced camshaft is made from a stock OEM core. The lobes are welded up, the camshaft profile is changed, and the camshaft is heat treated.
*DRI only uses this design because it is the most reliable option for this model.
Compression: 12-1 (race gas only)

Customer Cores Required:
Customer must send in to DRI their; Cylinder, Head, Camshaft for modification. (or purchase new cores
Kit Price is plus any OEM parts.
**For more Engine Kit options check the Buyers Guide section**