Mikuni adjustable bowls

[scotth]

I'm rebuilding two 36mm Mikunis from a 340 F/A. My question is where to start with the bowl (main jet) adjustment screws. With the plastic caps installed on the screws you get one turn of adjustment out of them before the plastic cap contacts the carb bowl.

Do I bottom them out; so as to run only off the main jet and then install the plastic cap? This would allow one turn out to richen up the main. Or do I go one or two turns out and then install the cap?

The reason I ask is that when I dissassembled them one was about 2 turns out and the other about 4 turns out with the caps installed. What's my starting point?

I also need the little o-rings that go on the bowl adjustment screws if anyone knows of a part number.

[wigman25]

Bottom them out (gently) and then snap the caps on so that they touch to the left of the knob on the bowl, that was the factory setting. You should start out running them at about 3:00, lean them up as conditions permit or as you change to bigger jets. When I was running the exhaust temp gauges, with stock jets they would usually end up between 6-8:00 for optimum performance, but every engine has it's own sweet spot. Wig

[scotth]

Thanks Wig - that's kind of what I figured. This is on a stock 340 Kohler F/F with 220 mains. It just threw me off when I took them apart and the bowl screws were 2-4 turns out.

...... I also found the o-rings I needed at Napa.