mikuni on a gs 750

[Guest]

I have a set of mikuni carbs on my bike with a 4 into 1 header.I have 120 main jets and it seems to pop abit when i let off the gas.Would going to 125 mains work better or be to rich?.Is there anything else i can change?.

Bill

[tkent02]

I have a set of mikuni carbs on my bike with a 4 into 1 header.I have 120 main jets and it seems to pop abit when i let off the gas.Would going to 125 mains work better or be to rich?.Is there anything else i can change?.

Bill

What year 750?
Pre 1980 has VM carbs, the mains have nothing do with close throttle mixture, use the air screws or fuel screws underneath.
They can pop from being too rich or too lean, it's hard to tell from here.

If it was made after 1980, post your results when if and when you get it right.

[rosco15]

Not sure what carbs you have, but on mine it would be the pilot jet.

[rotty]

i have a 84 gs 750 (canada only). i have rs34 flatslides... i have them set up from the factory..so maybe i should play with the screws?.

[rosco15]

The screw is kind of a fine tuning adjustment for idle. So backing the screw out a bit would give you more fuel at the closed throttle position, but not as much as going up on the pilot jet. Normally the screw is 1/4-1/2 turn out. How does it run other than that?

[rotty]

The bike runs nice at idle and it seems to have alot of power but when i gear down it pops on m.My bike seems to be running a little hotter since i put the new header and carbs on.I am assuming it is to lean.

[rapidray]

Yes, it is a lean condition. Raise the needles 1 clip position & go ride it. Let us know the result. Ray.