Help diagnosing motor problem

[Slim massie]

I have a 1996 mercury 25 hp took it out on the water one day and ran perfectly fine for most of the day. Was headed back to the boat ramp and all of a sudden it cut out and died. Motor would start back up but would die when I put it in gear. After getting back home I put the muffs on it and it ran perfectly fine. So after reading a few things I decided to take the carb off and do a thorough cleaning of it. There was a little gunk in it but wasn't to bad and it appeared the float was setting right according to the specs I found for it. So I put it back in the water and same problem motor would fire up and idle way down then when put in gear it would die almost immediately. I have also changed the fuel filter and have put new fuel line and bulb on it with no fix. So now I'm down to thinking it could be a coil pack. Does this sound like a symptom of a bad coil pack.
Thanks for all the help.

 

[Coxwain]

I really don't know, but can you check the omh readings on your stator?

 

[hermannm]

I had a similar problem and water was getting in the cylinders. Have you checked the plugs?

 

[racerone]

The common thing is to jump all over the carburetors / fuel system.----But first you do a compression test.---Then do a check for strong spark on both leads.----They will sound wonderfull and run " just fine " on a hose with one cylinder dead.

 

[nipperdog]

The common thing is to jump all over the carburetors / fuel system.----But first you do a compression test.---Then do a check for strong spark on both leads.----They will sound wonderfull and run " just fine " on a hose with one cylinder dead.

Amen, they will start up and sound just great with a whole bunch of different stuff wrong with them on muffs. This is solid advice IMHO.

 

[Renn90]

The common thing is to jump all over the carburetors / fuel system.----But first you do a compression test.---Then do a check for strong spark on both leads.----They will sound wonderfull and run " just fine " on a hose with one cylinder dead.

Agreed. verify the basics first. If the compression and spark check out okay, seems like a fuel issue.
Incidentally, I've rebuilt carbs on four different motors, and each time it solved an issue or made the motor run better; but none had any visible gunk or obstructions.

Had a similar problem where the motor would run great in all ranges in a barrel, but bogged down and sometimes stalled on the water. Turned out to be a sticking inlet needle. They can stick to a point that it will hold up the float. greater possibility of being the issue if the needle has no return clip attached to the float.