Low erratic Idle 1979 Johnson V4

" I have a 1979 85Hp V4 Johnso

" I have a 1979 85Hp V4 Johnson that occasionally will only idle at only 500 rpm when started and stall when throttled. Usually when warm it will start and idle smothly at 1100 rpm and throttle up to 5,000 rpm without a hickup.
I have changed the plugs
Changed the fuel pump diaphram(hopefullycorrectly)
as well as the fuel lines, water pump and thermostats.
I have not checked the timing, but I pulled the fuel line and cranked it to observe flow and lack of bubbles.
I also drained the fuel and sprayed the carbs with carb cleaner. I pulled off the bowls which looked clean. My compression is 112, 110, 108,110

Any Ideas? "

"Ray,

Intermittent problems

"Ray,

Intermittent problems can be tough to diagnose. My best guess is that you have an ignition problem that comes and goes, or that a carb is flooding.

The next time this happens use an insulated tool and remove the plug wires, one at a time, while the engine is idling. If you don't notice any difference when you disconnect a plug wire then you will have a good idea where the problem is.

Also, squeeze the primer, and see if you detect any fuel being pumped past the float chamber of either carb. This would indicate flooding in that carb caused by a bad float or valve.

"