I've been told that the reason my header pipes are turning blue is because I'm not jetted properly. My question is am I running too rich or too lean? And at the risk of sounding dumb I've always assumed that a smaller number jet is leaning the mix. Am I wrong? How off am I? I run a DMC Alien with a 157.5 on the right and a 152.5 on the left.(approx. 1200 ft above sea level) I've been told that the pilots and needles don't need to be changed unless their are major motor mods involved. The blue pipe doesn't bother me at all unless their is something wrong. My bike runs great and I've had virtually no problems with it. I thought the blue was just from heat. You might be able to see it my pics. I would appreciate any response from someone who knows what I should do.

 

It could be that it's just your idle mixture and maybe the pilots that are a bit lean causing the pipe to turn blue.
Yes a smaller # main is leaner.
What air box mods if any do you have?

 

K&n filter not pro-flow and two huge holes(4in & 3 1/2 in) cut in the lid w/ outerwear material around filter and screening the holes.

 

Your probably fine, I would pull the plug and check the color and try adjusting the idle mixture screws.

 

Thanks for the advice, Ill check it out.

 

I,m having a similar problem, but the techies @ yoshi said that my head pipe is turning colors because its titanium. I havent had the pipe long but i am going to jet it soon and I was told 160 left- 165 right because of the pro flo system

 

I got the following tip from a Dyno tuner and not sure if it will work as I have not tried it myself. You will also need a special screw driver that has a 90 degree bend in it.

The tip goes as follows. To get the mixture right, start the bike, warm it up and let it idle. With the special screw driver turn the mixture screw till you hear the rpm starts going up. When you get that turn it a little back and your set. Do this for both carbs.

Make sure that when you are done you do the following. With the bike idling, blip the throttle and let go... the bike must rev up very smooth and quick and settle down to idle almost immediately. If it stutters, the mixture is wrong. Also if it revs ok, but take a second or longer to settle back to idle, the mixture is to lean.

 

Guys, Dont forget the choke will colour your pipes!!!

 

Hey Punker660, do you own a kfx80 and if you do are you running PIPE ON it and what size of jet did you go with? Thanx