[madsledhead]

Hi,

    I moved the spark timing 1 1/2 deg adv. last night and tested it out on the trails. I deffinetly want to keep it where it is because the midrange boost was incredible.
    Looked at the plugs after 8500 rpm run for a short run (1 minute) and they seem right where I want it. Light sand on carb side with a small hint of sand/white on the exhaust. Maybe a little bit lean - but it was -18.5 C out. I normally ride at -10 C.    
Here's the problem, I ran in the mid range for quite a while and was disappointed that it was too rich. piston is nearly all oily and plugs are dark brown.

Should I go up 1 size on the mains before changing the mid-range setting because the increase in engine heat will make the top end even leaner, or does it not matter because at that stage the needle has no effect.
I am tending to change the mains first anyway but I want to know if you guys think it could be safe.

Also, what color plug are you guys shooting for, all my buds are too conservative - I run hard and always strive for top performance but not if it's going to cost me an engine.

Thanks in advance.

 

[michahicks]

I don't understand why you want to change the mains  assuming your 8500 rpm run was at wide open throttle (WOT)?
You say the color of your plugs was OK. Sounds like all you need to do is raise your needles to clean up your midrange.
AL

 

[madsledhead]

thanks for your response,

I was hesitant because I worry that increasing my burn temp from mid range will add to too hot a burn at WOT.

I think I will try to keep the rpm's down and try to get more heat in the mid range before I re-evaluate the mains.

 

[skidplate]

If you think you are  too rich in the mid range maybe try changing needles.  Whatever number you have perhaps try one number smaller Like, Instead of a R13--- try a R12--- This number is for 1/2 to 3/4 range if you are maybe in the 1/4 to1/2 range then you have to change the last letter on your needles.  A "G" is richer than a "J" so you want to go one letter down.  Changing your c-clip could be an easier way by letting your needle down one notch.  Lots of options Good Luck.

 

[snowmobster]

I would go up one size on the main and raise your needle clip one notch. [ lowering the needle ] because there should be no white color on your plugs after a hard run.