'03 WR450F Woodruff Key Blues
Posted February 20, 2003 - 09:08 AM
The local Yamaha shop saw some damage to the flywheel due to slipping and key breakage. Yamaha sent a new flywheel with instructions to lap it onto the crankshaft, apply loctite to nut and torque to 47 ft/lb. Got the bike just in time for the San Angelo, Texsas hare scramble. I changed main jet to 155, pilot to 48, air screw out 2 1/2 turns. Had no problems with the flywheel for 3 practice laps Saturday and 3 race laps Sunday. Jetting still seems lean. Good mid-range, but need more pull on top; and difficult to e-start unless the engine was very warm. Oh, my bike serial number is 1357; right in the middle of the bad batch!
Posted February 14, 2008 - 07:08 PM
Posted February 14, 2008 - 09:49 PM
My 2003 failed after I brought it home from the dealer and started it in the garage--- zero miles on new bike. No one knew about the "backfiring causes the woodruff key to shear" issue or how to cure it in January 2003. I eventually incorporated the complete idler gear mod using the 2004 WR starter idler gear and new gear cover. This is the only way to eliminate the sheared woodruff key problem permanently. I never had a problem after the update. I ride in Northern Baja California often--- sorry to hear about your problem.
Posted February 15, 2008 - 07:41 PM
I'm affraid you are out of luck.
Posted February 16, 2008 - 08:30 PM