New Forum Member - Red Hot Pipe and Surging Idle


I've just found your forum and would like to introduce myself. I just purchased a 2005 WR450 FT. Brought it home today. I will to spend a good deal of time tomorrow reading and learning.

I spend a 1/2 hours or so with the initial break in. I noticed the header pipe quickly started to glow red. Is this because of a restricted idle or is this normal.

I am also experiencing a surge at idle and even after a 1/2 hour that has not smoothed out. Is this because of a lean mixture or retarded timing?

Tomorrow I'll be following up on what I have learned about the idle stop and 'grey wire'. But now with the way the bike runs I’m thinking I've got a bit of work to do.

This will be my 11’Th bike. Many, many dirt bike, all the way back to CZ's. This bike seems very restricted. But from my little ride tonight I'm going to be having a lot of fun.

Thanks for understanding a new forum users simple questions.

Keith Morris

Quilcene, WA

if you do a search of these forums you will find a ton of useful information on this subject and others. In a nutshell your bike is running lean, you need to richen the carburator mixture a little bit.

I forgot mention. Welcome to TT, this place is a wealth of information.

Thanks WR450F_RDR

I"ll do the research. I'm a little blow away that these engines would get so restricted. Or maybe I'm not....



Do the free mods at thumperfaq.htm, even though they are for 250s. Then, richen her up pursuant to the jetting guide on this forum. You'll be good to go!

Hi and welcome to TT. (your jetting is LEAN)

For Info there is a similar site in AUS but TT is more informative IMHO and reaches a wider audience. The AUS site seems good for hooking up ride locations and local info...

Thanks WR450F_RDR

I"ll do the research. I'm a little blow away that these engines would get so restricted. Or maybe I'm not....



I questioned a Yamaha dealer in AUS about 3 months ago re. WRs.

He told me:

1. They arrive in AUS with AIS that is required for Calif. desmog regs. but Yamaha Australia remove/derestrict it before it heads to the dealers

2. They also mod/change the thottle stop to YZ spec, and

3. Pull the end baffle out of the exhaust...

I dont know the truth in all this, you know dealers.. tell you what you want to hear? This is just a heads up for you if you find any of the above already done.

Also try:

the stickies at the tops of the forum and

which has a lot of applicable mods for the 450 as well

Enjoy the bike


Red hot pipe will go away once you ritchen it up. Its very lean now and will get worse with the air box and exhaust tip mods.

you'll also want to read this about breaking it in

Don't just do a brakin on the stand.

Thanks for all the responses. Can anyone tell me a source for the JD jetting kit and air/fuel adjusting screw? I did order the ais kit and wonder if any jets are included. Seems to say so.

I'm still just blown away a bike can be sold that would allow a header pipe to glow red. My first ride was last night (as soon as the bike came off the back of my truck) and the glowing header reflected red on the ROAD. Jeez!


The JD kit can be bought here at the TT store,

Yeah, I was supprised about the pipe too. I gues safety falls behind the quest for clean air...One jet change and a fuel screw will take care of that.

If you ordered the TT store AIS no jets are included. The Yamaha kit does include the YZ t-stop.

Its just as easy to shorten the stock one though.


You can order the kit direct, and have it in one day from JD themselves via usps basic charge. They also have the Zip Ty screw Ex-Hard. You will have to pay tax because you live in WA. but no delays. This has been a great forum to get others experiences. I was told that a glowing header pipe was normal when I first got my 05. I just re-jetted (168, blue 4th, 1.5 Zip ty, snorkel and cut outs on air box, grey wire, YZ throttle, AIS removed Non kit, exhaust insert out) and my header does not glow anymore. Only about 2 inches glows a light red, and throttle response is better. So, yes they glow red stock, but properly jetted they will not.

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