Loss of Fire

[MIKIEGJR]

Good Afternoon, the problem I'm having is with an early 90's Mercury, 3-cylinder 90 Horsepower engine. After around 5 minutes of running time the motor completely looses fire, and will not crank up. It would be just like pulling the kill switch. Changed out power packs and motor done the same thing the next day. Its like once something gets warm all fire is lost. This happened to me last Saturday. I walked by it yesterday which was Tuesday, hit the key and it fired right up. Ran the motor on the hose and once again ran after around 5 minutes then killed like you would have turned off the key.... Any Help appreciated.. Thanks, Mike

[rchevelle71]

Not sure if this is true on the smaller motors, but check the coils. I once had a problem on my 250 where a coil was shorting out, and since they had a common ground, it was causing them all to short. I diagmosed it by removing the wiring harness to one coil at a time until it fired on the remaining cylinders.

[Capt.Insane-o]

Get a dva meter and check the outputs on the blu/red stator leads after it quits.

[MIKIEGJR]

I will check both of the above suggestions. Thanks Very Much for the input!

[Capt.Insane-o]

If your is an early 90's model it does'nt have the cdm's, it's a regular ADI ignition and a coil issue will not cause your symptoms.

[MIKIEGJR]

Its the Gray Stripe split covers, I think they started those around 1988 and went into 90 something. I know it has 3 Coils on it and one power pack. Kinda played around with it a little while yesterday until I could here them testing the race boats down the road from my house. Then I lost all intrest and took off...lol

[mn808gade]

see post #3