426 idle problems

[ezzrigby]

I have a 01 426 been running badly won't idle off choke at at, striped the card down found nothing but it seems now it will idle off choke still a little rough up and down revs alot, but once i got it to idle i noticed after about a minute the front exhaust pipe went a bright cherry colour. Any ideas? I can't see this being right somehow!!

[1998YZ400F]

ive heard the glowing pipe is a common thing on these bikes and its nothing to worry about.

[grayracer513]

You need to familiarize yourself with adjusting the idle mixture:

http://www.thumperfaq.com/jetting.htm#PJ

[jayh300]

come on gray...... you know we need to see it every so often...

[grayracer513]

What? Evidence that glowing header pipes are not so unusual?

OK:

[jayh300]

that's the ticket !!!! thanks gray, after a long day at the grind, that pix always makes me laugh...

I would still like a ride in it !!!