1995 Johnson Ocean Runner J150EXEOM problems after engine warm up.

trophyjim

Recruit
Joined
Oct 12, 2011
Messages
5
Hi All,

About 1 month ago, we took the boat out to enjoy a day of fishing. We reached one of our favorite spots about and shutdown the engine and anchored up. The ride was about 20-25 minutes long. When we first got under way I noticed an erratic reading on the tachometer then it just went dead and never recovered.

When we were ready to change locations, the engine started but shook violently. I immediately shut it off and restarted. The engine ran normally. We reached location #2 and anchored up. About 2 hours later the engine would not start.

After being towed in, we took the boat to the house. I did a little research and we tested various things per the troubleshooting guide in the repair manual.

We have replaced the power pack(OMC), 3 ignition coils, and voltage regulator/rectifier. The engine starts and idles great for about 15 minutes, then the engine develops a horrible miss.

My marine mechanic buddy suggests the stator is breaking down when the engine gets warm.

Any thoughts?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
Re: 1995 Johnson Ocean Runner J150EXEOM problems after engine warm up.

Is your motor equipped with a warning system ?--------S.L.O.W.------This system limits engine speed when it overheats.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1995 Johnson Ocean Runner J150EXEOM problems after engine warm up.

Before I'd replace the stator I'd go to CDIelectronics.com for some correct trouble shooting procedures. Replace the stator if you just want to keep throwing parts at it. You could also have a bad OIS sensor on it.
 

trophyjim

Recruit
Joined
Oct 12, 2011
Messages
5
Re: 1995 Johnson Ocean Runner J150EXEOM problems after engine warm up.

Yes it has S.L.O.W. I eliminated the temp sensors by unplugging each one separately...the engine starts runs smooth for a few minutes, then violently shakes. I might want to add that I did measure the cylinder temperature with a handheld laser thermometer. The thermometer read about 168 degrees F on the average as measure at each cylinder head and thermostat housing. I did not get the S.L.O.W. overheat alarm. Pulled all the plugs(they are new also) and they were not fouled.
 
Last edited:

trophyjim

Recruit
Joined
Oct 12, 2011
Messages
5
Re: 1995 Johnson Ocean Runner J150EXEOM problems after engine warm up.

The original problem was NO SPARK on any cylinder. I used the CDI sheet that came with my less than 2 year old Power Pack which was a CDI unit to troubleshoot the issue, plus the repair manual, plus I printed out and used the CDIelectronics.com troubleshooting chart for OIS engines. I replaced the regulator/rectifier because the tach quit working.
 
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