I read somewhere that your jets are set properly if your exhaust pipe (Yoshi stainless) turns a nice gold color. It said if it turns blue it is too lean and if it glows it is extremely lean. Well after jetting, the pipe turned a beautiful gold color, but the first three inches or so of the left pipe coming out of the motor is blue. And after riding for a couple hours yesterday a little bit of blue here and there is showing up, but just barely.

Am I okay or do I need to go up a size on jets. I'm running 146 & 148 with no lid at an altitude of between 4000 and 5000 feet (Dyno jet recomended 144 & 146, but that wasn't considering no lid so I went up a step on each). Both screws are out 3 full turns. It rides awesome, the only thing I noticed was that after is was warmed up I had to give it a touch of throttle in order to start it, but other than that it seems perfect.

John

 

I think you may have to jet up. I was running that exact setup at 500ft.

 

When you say jet up, do you mean larger size jets? My understanding was that a higher altitude requires lower size jets. The air is thinner the higher you go, so you can't put as much gas to mix in with the "lite" air. I don't think I need lower size jets, if anything I think a step up, but I don't want to change it since it is running fine now, unless others think it would benefit my Raptor.

John

 

Check your plug to see what color it is. Black burn is rich, Brown like a paper lunch bag is perfect and, Gray to white residue is lean. This is the best way to start.

 

It's good to keep in mind that the headpipe on a Rappy glows bright red no matter what condition.

 

I found my pipe glows red, specifically on muddy mx tracks.

My plug is a little dark, can I lean it out with the mix screw and avoid having to rejet? It runs fine for me, I just rev the pi$$ out of it. But I let my buddy run it yesterday and he was easy on it because he hasn't ridden a quad in a while. When I jumped on, it was bogging a little, until I pegged it and cleared it out. Reminded me of my old two-stroke.