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I have a question on the float setting for the Mikuni carburators on a 1979 Suzuki GS 750 L. I just bought this bike, and the carbs were leaking from time to time. When I removed them and opened them, I could see why. The floats were set at .70 in. so they hit the top of the carb before they closed the needle valve completely. I have a Haynes service manual, and it says the adjustment for the floats is 1.02 in. This leaves only .27 in. travel of the float measured from the top of the float to the carb housing. I would like to know if this is the correct setting, as I don't want to run lean, but don't want flooding as well.

Thanks for your help,

Greg

i am not sure how you are measuring your float height. but the its usally done from the mating surface of bowl to the bottom of the float. meaning the side thats nearest to the drain.

.70" is 18mm while 1.02 is about 27mm which would make the level in the bowl much lower. i dont know the exact specs but if thats what the book says go with it. but its seems low to me. if unsure about the correct level. turn the carbs on their side an take a look. they float should be slighty lower then level. that should put you in the park.

its better to set the float a little lower then higher. if the carbs still leak gas out of the drain and it has an over flow tube in the bowl.( long brass tube)check the tubes closely for small cracks. (common) which will allow fuel to enter the overflow tube now matter what the level.

also make sure your book is listing the float height and not the fuel level!

That's what makes me question the specs given by the manual. Seems like a big differance to me, but I do know that .70 is to high, as the float hits the carb body before the valve seats.

You are correct Huh about measuring from from the bottom of the float to the mating surface of the bowl.

THanks,

Greg

if your still unsure do a fuel level check. put the bowls on,clamp the carbs upright in a vise and run some fuel to the carbs. take a length of clear hose and put on the drain spout. hold the line up the body of the carbs and open the drain screw. the level of fuel should be a little below the mating surface of the bowl and carb.(with no air in the hose) set it at a mm or 2 below the line of the gasket surface.

this should be good. if its too low the bowl will empty and starve for fuel at high speeds with a load. which will make the bike cut out. but shouldnt make the bike to lean any other time. unless its really low. too high and it will flood of course.

do the fuel level trick and you will be fine.

good luck

Thank you Huh, I will set it by the book, then check fuel level.

Thanks again,

Greg