Johnson 150 1987 Overheat Alarm?

[bob1008]

After cruising for an hour at 3000 - 3500 RPM's I tried running WOT. After about 2 minutes at 5000+ RPM I got a long steady alarm. Immediately powered down to idle. Alarm went silent after about a minute and a half. If motor did in fact reach overheat temp. would this be normal for the motor to cool down and alarm go off in less than 2 minutes at idle? Ran fine with no alarm after that at 3000 RPM.

 

[wilde1j]

Re: Johnson 150 1987 Overheat Alarm?

Check to see if, in fact, it is overheating at high power settings. If it is, then determine why (water puump, clogged water passages, bad vernitherm element, etc.)

 

[bob1008]

Re: Johnson 150 1987 Overheat Alarm?

I did give it the "hot hand" test and was not extremely hot. About the same as the twin. I'm wondering if the WOT could have caused some type of fuel alarm on that motor. I am still running the original VRO system.

 

[MGuckin]

Re: Johnson 150 1987 Overheat Alarm?

Steady alarm is also for excessive fuel pressure in OMC motors of this vintage.<br />Check for a kink in a line or possibly a restricted tank vent.

 

[bob1008]

Re: Johnson 150 1987 Overheat Alarm?

While checking fuel lines I noticed fuel dripping from the lowest horizontal line coming off the fuel manifold. Than I noticed it was actually coming from the bottom carbuerator above it. This bowl was completely full and overflowing down the sides while idling. Any ideas ?

 

[MGuckin]

Re: Johnson 150 1987 Overheat Alarm?

Incorrect float setting or defective needle valve & or seat.