Cherry red head pipe

5 replies to this topic
  • Longtimeyamahaguy

Posted May 07, 2006 - 05:47 PM


How normal is this? Start the bike up and within 3 minutes the head pipe is glowing red. From the head around the bend and right up to the power bomb area (FMF P-Bomb head pipe), also has a FMF power core4 w/quiet insert.

Bike is 2003 WR450, grey wire cut..... etc
jetting is a JD kit w/red fuel screw 48 pilot 168main
I`m probally at about 500ft elevation and its about 55 degrees outside

I just had the carb off to find out why last yr it ran soooo lean, thought I found a plugged up pilot and was all happy :crazy: that my lean condition would be solved. Started the bike up and still acts the same as last yr :ride:.

The bike has NO hesitation at all when reving it up but lots and lots of poping on decel!!!!!!!!!

  • YamahaWR450FMike

Posted May 07, 2006 - 05:56 PM


your running lean.

  • Longtimeyamahaguy

Posted May 07, 2006 - 06:09 PM


your running lean.

Ummmmmm yeah I know

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • mtrablue

Posted May 07, 2006 - 06:43 PM


there are a lot of reasons your bike could be lean. some as simple as the jet clogged again to the hot start cable has been pulled and held open. make sure the pilot fuel screw is 1.5 to 2.0 turns out. hell, for that matter make sure it didn't fall out. as for the pipe, it's normal. there's really no reason to run the bike that long just sitting there (unless your working on jetting).

  • theclone

Posted May 07, 2006 - 07:57 PM


The header glow is perfectly normal. All bikes do it.
But the popping means it's a little lean. Back out the fuel screw a little bit.

  • grayracer513

Posted May 07, 2006 - 11:26 PM


It's totally normal, and is not an indication of lean mixture. Retarded timing, because it's idling and is in neutral (which retards it further). Have some fun and run a quick search if you doubt me.


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.