1984 mercruiser 140 hp 4 cylinder Help!!

[jim arthur]

Ok I have compression{between 132 and 135 between all cylinders}
I have fuel pressure. Rebuilt carb and adjusted to specs. Fresh fuel in a clean empty tank. New fuel filter/ water seperator. New cap/rotor/ wires/plugs. Has correct electronic conversion kit in it. Timing is at 6 deg. btdc took out on water and pulled away from dock and started sputtering when given throttle. backed off and brought up slow and was fine. but only got to about 3000 rpm . got across lake and started sputtering and died out and engine temp was high. would not start back up. Checked fuel/good . Checked spark/good . had spark at coil and not at plugs. Replaced cap rotor and still no start. Before I took it out it seemed like it would run forever on muffs without getting hot.

 

[airshot]

Re: 1984 mercruiser 140 hp 4 cylinder Help!!

When was the last time your impellor was changed? How about spark plug wires including the coil wire? Sounds as though you may have a lean out condition if water pump is good. There is a very good trouble shooting section in the sticky/adult section at the beginning of this forum.
Airshot

 

[jim arthur]

Re: 1984 mercruiser 140 hp 4 cylinder Help!!

When was the last time your impellor was changed? How about spark plug wires including the coil wire? Sounds as though you may have a lean out condition if water pump is good. There is a very good trouble shooting section in the sticky/adult section at the beginning of this forum.
Airshot[/QUOT

Impeller is new. just bought plug wires as well as new coil and coil wire. new plugs just put in and look brownish black when taken out to check.

 

[beckwithdj]

Re: 1984 mercruiser 140 hp 4 cylinder Help!!

When was the last time your impellor was changed? How about spark plug wires including the coil wire? Sounds as though you may have a lean out condition if water pump is good. There is a very good trouble shooting section in the sticky/adult section at the beginning of this forum.
Airshot[/QUOT

Impeller is new. just bought plug wires as well as new coil and coil wire. new plugs just put in and look brownish black when taken out to check.

I Have a 1985 Merc 140 and I am having the same issue, changed the fuel pump, the the cap and rotor, rebuilt the carb, new coil, new plugs, and they are black ( well the first one is real dark, and they get less dark on 2, 3 , and 4 ) seems to run a bit rich for the color I think. but on Muffs it idles perfect and will run like it seems all day just fine, throttles fine. so finally took it for a water test, and pulled away from the dock, and when you throttle it sputters, spits, and dies. start again and same thing.
tried over and over, i was able to restart everytime, but it will not stay running when throttle in gear. after getting home i checked compression, and all 4 cylinders were right where they should be. I too am very confused. did you figure it out?