1989 5.7 OMC engine turns but won’t fire

[Nick_1987 5.7 OMC]

Hello, my first time asking a question here on iboats. I have a 1989 5.7 OMC and I was out last night, engine turned on fine, ran perfectly and out of no where while I was coming in to port the engine died. I tried to start it back up, the starter was turning but it won’t fire. I’m not sure what the isssue could be but the positive wire going to the ignition coil is very hot after a few tries. That’s all I have to say, any info will be much appreciated !

 

[kenny nunez]

If the rubbing block on the points wore off then the points are not opening and the ignition is permanently grounded. Pull the distributor cap and have someone turn the engine over while you are looking at the points.

 

[Nick_1987 5.7 OMC]

Thanks Kenny, I also noticed that there is no spark coming from the coil.

 

[Scott Danforth]

Service the points.
file them, gap them, verify the dwell, then set the timing

 

[kenny nunez]

If your engine has a Prestolite distributor the rotor lobes are susceptible to rusting which acts like sand paper that causes the rubbing block to wear out quickly. The cure is to convert to either a Mallory distributor with a brass rotor or convert to a Petronics electronic conversion.

 

[Nick_1987 5.7 OMC]

Ok here’s what I found out over the past few days, I replaced the ignition coil on and the positive wire is still getting very hot, so I took apart all the electrical tape the harness and everything was wrapped up in and I found no short. I think it might be a ground but I didn’t find out that before the ground going from the battery to the engine touched the positive going to the starter at some point in its life... these were wrapped up in electrical tape so I doubt that it’s the issue. I looked at the cap and everything looks good. I have no idea what could be the problem. I haven’t found a short yet... maybe a fuse? The 2 50amp fuse are good. Like I said before the starter turns the motor but there’s no spark. The coil does not get power.

 

[kenny nunez]

With the distributor cap off are the points opening and closing when the engine turns over?

 

[Lou C]

If you can post up a pic of the distributor close up. I have one of these and as long as it is not worn out they are very simple to service with new points, condenser and cap.

 

[Nick_1987 5.7 OMC]

Yes the points are opening and closing, I will get a pic of distributior with cap off tmr

 

[Scott Danforth]

with the distributor cap off, put a dwell meter on the coil. if your dwell is 26-31 degrees while cranking (per service manual #3) , then you are gaped correctly and the condenser is good and the points are working.

 

[Nick_1987 5.7 OMC]

Got it running boys

 

[Lou C]

great what was the cause of the non start?

 

[Nick_1987 5.7 OMC]

It was a loose wire on the starter coming from the harness I guess I didn’t check everything before ordering stuff. But I have spares now