1982 GS650G carb tuning advice

[Guest]

Rebuilding a suzuki gs650g, i've put pods on it, and finally got it running consistently. I've put in new plugs and after about 5minutes running this is what they look like.

I suspect its running fairly rich. Can anyone recommend the best way to adjust the mix?

thanks!

[terrylee]

Do a search under plug chop and you'll find lots of threads on how to do one and what they will show. Kool-Aid Kid has a useful thread on how to adjust your mixture screws. terrylee

[Steve]

I've put in new plugs and after about 5minutes running this is what they look like.

"5 minutes running" under what conditions?

Idle?

Part-throttle?

Full throttle?

Did you do any jetting changes?



.

[Oliverstrother]

Just idling from cold, a little bit of revs now and again.

[Oliverstrother]

And no jetting changes so far. Standard set up. I think part of the problem is the mix screws are already about 4 turns out. Can't really lean it out anymore. (I think that's how it works).

[terrylee]

You should have cv carbs. on the bike. Screws get turned out to richen mixture and in to lean mixture. Start at about 21/2 turns out from lightly seated. (righty-lean,lefty-rich). terrylee

[tkent02]

You should have cv carbs. on the bike. Screws get turned out to richen mixture and in to lean mixture. Start at about 21/2 turns out from lightly seated. (righty-lean,lefty-rich). terrylee

Really it's best to read a little about the process before tuning anything. Having the mixture screws that far out will definitely color the plugs.

[Oliverstrother]

ok thanks. I checked the spark plugs and 1, 3 and 4 were pretty sooted up. I've screwed them all in 1 turn. So hopefully this will improve their behavior on the idle jets.

one thing i noticed is that it now takes a little longer to climb down the revs. I'm going to keep adjusting the idle screws until i get satisfactory performance from them. I guess I'll have to do the same with the needle jets and the main jets.

[tkent02]

ok thanks. I checked the spark plugs and 1, 3 and 4 were pretty sooted up. I've screwed them all in 1 turn. So hopefully this will improve their behavior on the idle jets.

one thing i noticed is that it now takes a little longer to climb down the revs. I'm going to keep adjusting the idle screws until i get satisfactory performance from them. I guess I'll have to do the same with the needle jets and the main jets.

Better with Mikuni BS series CV carburetors to follow Mikuni's procedure, which is too tune the main jet first, then jet needles, then work your way down. To the mixture screws last. This is because on this model everything is affected by the main jet. Compltely the opposite of tuning the older Mikuni VM carbs where you would do the pilot circuit first, then work your way up..


What does climbing down the revs mean?