79 GS850 Carb 3 sooty

[Guest]

Hi all,

My new to me 850 is a rebuild from a chap in Victoria BC. AZR from this site was good enough to help me out last year on jetting and such. It has a K&R filter, 4 to 1 Vance and Hines...
My current issue is plug #3 is sooty... very.... and has been pretty much constantly. I've played with pilot and air screws a lot... No I haven't cleaned the carbs yet and it may be in my future this summer...

What I did do was replace the Pingle petcock with a brand new (and expensive) stock susuki petcock (because I had it around from a previous bike). I have to say the new petcock seemed to make the bike run better but that may be just because I was used to 10 years of a vacum petcock and really had trouble remembering to turn the Pingle off constantly. Having the vacuum to #3 hasn't seemed to solve the #3 sooty issue at all.

I did adjust the valve clearances late last season.

Anyway I'm wondering what you all think. Might it be worth say checking the #3 float level? I'm laughing as I say this and pretty much know the answer. Clean the carbs... but any other thoughts?

Thanks

[Spyderman]

check your vacuum diaphragm on your petcock carb #3 provides the vacuum to activate the petcock if it is leaking through the diaphragm then it will give you a rich condition on cylinder #3