Mikuni BS34 Air & Fuel Circuit Diagram

There it is... hope this helps!



Cheers.

Thanks for the diagram and directions on setting up the pilot jet screws; I didn't realize the part about turning all the screws the same initially, so that will help.

On the diagram, it doesn't seem to show it, but when I was cleaning the carbs with the tops off and the slide/diaphragms out, I noticed that opening the enrichener opens a wide port on the outside of the carb (sorry, I didn't think to get a picture); this, I believe, causes the slides to drop down to help with cold starting (although I'm not sure how that helps); when I was testing to see if the vacuum would hold the slides open (by pushing the slides up and holding my finger over the horizontal air slot), the slides would fall immediately if the enrichener was open. Seems strange that there would be an unfiltered air pathway into the engine, albeit only when the enrichener is open, and then it has to go thru the small hole at the bottom of the slide.

I'm not sure exactly what your speaking of without a pic, but there should be no ports that open to the outside air on the carburetors at any time.

I believe you may be refering to the vacuum ports... and those should be capped off. If you have a vacuum operated pet-cock, then a line goes from one of them to the vac port on it.

If there is any other hole exposed to open air for any reason, plug it. No open air.

Cheers.

No vents?