Mikuni vm32 both fuel overflow!

joevirus563

Coast to Coast
I've done a rebuild a few week ago. Now I have a few issues to fix. One if them is the following.

The engine wasn't running nice at all. Remove the carb bowl and clean up the Jets. That's it!

After putting everything back together, the carb are pissing from the overflow. Remove everything twice to readjust the stop plate! Still doing the same thing. After checking out, the needle does seals well when I close them manualy no fuel is coming out.

I've check the float as well and the are fine!

What the hell I'm I missing?

Both carb at the same time??
 
Did you set the float height? Float height is 24mm I believe but you better verify that. Also check the overflow tubes inside the float bowl, sometime they develop cracks that allow gas to leak out. Do you have a float bowl gasket on the carbs? If so, depending on the type they could be interfering with the float preventing it from moving up.
 
I'll check the gasket on it. Those are brand new carb so should not have any crank in both carb at the same time.

Also 24mm with carb reversed right?

What part are you measuring?
The part that push the needle or the legs?
 
Yes, carb upside down and you measure distance from bottom of float (top since carb is upside down) to the lip of the float bowl. You can get manual for the VM series here: http://www.mikuni.com/pdf/vmmanual.pdf
 
Usually you don't want to do it with the carb upside down completely you want to go at the angle where the float just rests on the plunger without actually depressing it.
 
I've seen it happen after a rebuild - if you're sure the floats are set right then the needles and seats are most likely stuck open. Sometimes, especially with ethanol gas, it can happen. Tap each float bowl lightly with a small hammer and see if they stop pissing gas.
 
Found it...

I've reset the floats to the stock height 24mm and problem is gone...

What the hell is that... I don't know but it works.

Not I have to fix my idle mixture.

It starts fine on choke but when I remove it, it slowly dies.
Will try to ajust the air scren (3 turns out) to 1-1/2

Thanks.
 
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