1985 johnson 120

[ram4fun29]

I'm having trouble getting engine to idle, when it doe's it seems to be low. tach is showing 700 to 800 rpm's. pulled plugs are not sooted up some blackening, and slightly wet. The power head is new and i'm still double mixing at 50:1. after idling a couple of minutes starts smoking and dies. It ran good in the upper rpm's for a while 5600 easy then after about 30 minutes starting at 4800rpm's it developed a vibration maybe a miss rpm's would not climb as they did earlier. was told more than likely jets on the idle and maybe a coil breaking down or water in the gas on the high rpm problem. doe's this sound right thanks chris

[Jeff_G]

Did you do a compression test?
50 to 1? with the VRO working too?
With motor running using plastic pliers pull plug wires off one at a time and see if there is a difference. Hook up timing light to wires one at a time to verify ignition too.
Put some of the gas in a clear glass jar and check for water.
If you can run the motor in the evening and look for ignition leakage, pull plug wires and check again. If leaking will spark from that point to ground.