where to start, picked up 03 wr today

i just picked up my new wr today. first i removed the throttle stop screw and sawed off everything but the threads. then i took the stock exhaust that came on my yz450f and put it on the wr. it fit great with a little basement engineering. now i need to know what would be the best jetting to go with and any other free mods or adjustments that i need to make. i must have been living in a cave or something, but tonight is the first if read about the key shearing. i don't know what that is or what it does. could someone enlighten me and let me know what i need to do. the bike has only started twice using the button. i have had to kick all the rest of the time. this is my first wr so any info would be truly appreciated.



The Woodruff key is shearing apparently because the nut holding the flywheel on is not torqued properly. Its on the left side under the cover by your gearshift. Please check to see how tight it is from the factory and let us know. then locktite it and torque it to 47 lb's (some manuals say 61?? not yet clear which is best. ) Of the bikes that had a problem, no one knows how loose the nut was to begin with.

The jetting seems to be lean, there are many threads going about jetting, it will take a while to truly see what works best. probably going up to a 155 or 160 on the main. 48 on the pilot and raising the needle by lowering the clip a notch or two. that should get you in the ballpark until the dust settles.

Good luck and enjoy, be sure to let us know how tight your flywheel nut is tightened (Soounds kinda personal doesn't it) :D:)

Jim, Congrats on the new bike! I just got mine today also. Took it for a quick blast down the street. It runs good. Be careful with choping off the whole throttle stop screw. I have heard of problems with the position sensor. You may want to buy the YZ screw, that's what I did. The woodruff key that people are talking about is the key on the crankshaft (left side) that hold the flywheel on. The Yamaha manual calls it the "rotor". Check the nut for proper torque - 47 foot pounds.

Good luck!


do you have to take the whole case off to check the rotor nut or can you just do it through the cap you unscrew.also do you have to drain the oil to do it?

The inspection cover will allow you to put a wrench on the mag nut. Real easy. :)

hello jeff in oregon. thanks for telling me about the throttle stop screw. do you happen to know the part number for the yz screw. i definately don't want to take any chances on tearing anything up. my dealer's mechanic said to cut it off up to the threads, but i feel more confident on advise i get on TT.



Do not cut it to the threads, it will be too short. There is a post here I think with the yz 450 PN. If not just get one from your dealer. I have already cut mine and received a yz ts bolt but I have been so busy getting it street legal (done) that I haven't posted the length. I will do that as soon as I can, and also comment on jetting and torque info, which I will be working on tommorow.

Hey Jim, the p/n for the YZ throttle stop screw is



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