Re: 94 Johnson 200 Ocean Runner won't idle when timing set 4 ATDC per manual
If spark and compression are good, it will idle at 4* atdc with all butterflies closed. So, seeing that it doesn't, I would be looking at the idle circuit fuel feed. In each carb, there is a small brass tube that extends down into the bowl. That is the source for idle fuel to the engine. Make sure all tubes are clear, follow circuit thru the side labyrinth chamber behind that metal plate and clean accordingly, follow circuit on through to the throttle bodies, and clean behind the core plugs. That is the idle circuit. Another thing I do is when running at 2k rpm or so, I clamp my hand over the mouth of each carb sealing it off completely, for a second or so. When you remove your hand, if carbs are working right, raw gas should pour out the front of the carb throat. All cyls should respond the same way. If you have a carb that does not pour gas out, then look at the center ring of the bowl gasket for air leaks there.