Re-Jet, Q-

[850g]

Hey all, im new to tuning the GS's so heres the question>
I have '80 GS850G that I put a Jardine exhaust and K&N filter on..The stock main jets are #115 and the kit I bought has #100, 110, 120 and 140. I put in the #120's and it still feels a little thin, the plugs are fine color wise, it idles fine once warmed and responds alright. I'm thinking the #140's would be to fat for the stocker only if I had say 10.5:1 slugs or a ported head. I'm thinking it might need #125-#130's....??
Anyone with GS tuning knowledge I would be thankful for any tips, thanx.

[KEITH KRAUSE]

I'd try 125 mains.
Not sure what throttle position(s) you got the plug reads at, but you have to test the main at 3/4 to full throttle, full being the better test.
Test at 1/3 throttle to see what the jet needle circuit is doing. I would think the jet needle is lean.
A 1/2 additional turn out on the mixture screws might help.