i added a fmf silencer, and now the headpipe glows red. i upgraded the main jet to a 170 like the fmf website says, but it still does it. the website also stated to turn the fuel screw to 2.5 turns out whereas the stock is 1 1/4 turns out. will doing this help? any suggestions would be great

 

Where is your needle jet?

 

where is it? the clip u mean? it's at the 4th clip

 

It should help, you're running a 170 main jet?

 

i run a yoshi slip on i added a 172 main jet changed the needle to #6 position and took off the airbox lid runs awesome now

 

What year of YFZ do you have?

 

If the bike runs fine I wouldn't waste your time rejetting.

Do a search on this topic and I think you will find that this is VERY normal. Mine has done it from day one. I have five buddies that all have the same thing on their bikes. These machines were made to run and run hard. They don't like to sit and idle.

Again, this is not a jetting issue.

Buck

 

I agree it is normal for the headpipe to glow.
I run a DR D silencer and airbox lid removed.
My jetting (for sea level) is as follows:
45 pilot
Stock needle 5th clip position
172 main
2 1/2 turns out on the fuel screw

Hope this helps.[img]i/expressions/face-icon-small-wink.gif[/img]

 

MINE IS AN 05

 

I have an 05 yfz450. No air box lid, curtis sparks jet kit, and intake kit. Curtis Sparks pipe....the my head pipe glows red too. Same thing with a couple of guys i ride with.