Mikuni 36 Float Height

Carb is open right now to re-jet with JD kit. I have read several things about float height in passing, but what is the correct height for the floats, how do i adjust it, and how do I measure it? Thanks!

Also, when y'all replace gaskets and diaphragms in the carb, do you put a little bit of oil or fuel on them to help make a better seal?

13mm. Now to describe how to set or measure. Carb in hand. Float bowl off. Tilt carb sideways so that you can see the floats move and flop a little. Slowly tilt until you see it stop. Measure distance. If low or high a slight tweek of the metal between floats until it measures 13mm. With out a carb in hand I cant tell you exactly where to measure because I cant remember. No oil or fuel on the gaskets or diaphrams. Sorry I am not much help. Hopefully an expert will see this and chime in. Be sure to check the float needle for condition. If grooved you should probably replace it to save future fuel leakage problems.

I found another thread and measured it (pretty roughly) to be 0.5 inch = 12.7 mm so I think its fine. Rubber needle seems to be in perfect condition. Thanks for the reply

Also, when y'all replace gaskets and diaphragms in the carb, do you put a little bit of oil or fuel on them to help make a better seal?

I do not use anything on the o-rings or other seals.

Whatever you do do not put oil on anything rubber. The oil will penetrate the rubber and it will swell up to a size substantially larger than it should be.

Some rubber-like materials are not subject to this but I'm pretty cautious to not experiment with my carburetor parts.

Float heght is 13mm +/- 1mm.  Best to set 13 to 14.  I would lower your float a bit.


YES lubricate the rubber O rings with oil, grease, silicone, or special O ring lube.  Not very critical what you use but do use something.  Not all ribber is the same. The rubber seals in carbs is fuel resistant. Gas and oil is fine on the O rings.


Do not put oil on rubber intended for brake fluid. Do not put brake fluid on rubber intended for oil.

The needle has a tiny spring built into it and there lies often the problem. It may get stuck in its compressed stance by corrosion, dirt, and then the float will 1) press too hard on the needle, damaging its tip (avoiding this is what the spring is for) and 2) the fuel level will be too high.


So it may be thought that the float needs adjusting when really it's the needle that needs to be changed.

Nothing was wrong with it, I just wanted to check it while the carb was out and open. Just did JD jetting, and bike runs great! I didn't put any oil/gas on the gaskets, oh well. :(

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