RED HOT pipe!

Sorry about the previous post. WRONG EMAIL. If you can help me please send me an email at:

OK, I reinstalled my stock pipe and it is still glowing RED! What gives here?

Here is my previous question: I just put my stock head pipe and silencer (minus the baffle) back on my bike to do some trail ridding. The changes from stock I have made are a 172 main jet and I have changed to the YZ timing. I just cranked the bike up and let it warm up and the head pipe is GLOWING red hot! It starts at the head then starts moving down the pipe! PLEASE can anyone help? Is this normal? I think the pipe is bolted up correctly. Thanks, Brad

That's usually a sign that your jetting is lean. Probably very lean if it's that red!

Seems to be normal. Happens to stock bikes with stock jetting also.


I could easily be mistaken, but I thought Clark, our super-duper, walk-on-water carb specialist, warned against the YZ timing and stock jetting. He may have been referring to removing the octopus, though.


I thought I responded to this before. After you switch to YZ timing you need to bump the PJ to a minimium of 48 and about 1.5 turns out on the fuel screw. The main should be between 178 and 182. You 172 main seems lean. This is good from sea level to about 4500 feet. Your stock WR needle (98-99 WR needle DTM, 00WR DRS) will work but is not optimum. If you you have a 98 0r 99 WR you should get a DVP and run it in the #4 position or a DVR and run it in the number 5 postion. If you have a 98 or 99 you can get by with a 45 pilot if you run the fuel screw between 2.5 and 3.5. HOWEVER, at altitudes below 2500 feet you should go with a 48 as a minimum. If your rides start at appproximatly 4500 feet and always go up in altitude then the 45 will work.

If you have a 00 WR with the stock DRS needle then the minimim PJ is a 48 up approx 6000 then drop to a 45.

That said if you start the bike at night and let it idle for any length of time the stock header will glow red and if your jetting is lean the color will head toward orange and the red will expend furhter down the head pipe. The 00 WR is jetted leaner from the factory and if you go to YZ timing then you must jet up or it will be too lean on the pilot!!!!

Let us know what year WR you have and more specific jetting can be recommended.


[This message has been edited by Clark Mason (edited 05-21-2000).]

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