Overheating......Again!

[scottie]

OK, I am just about at my wits end. I have an 89 Bayliner with an 85HP Force L-Drive that keeps setting off the temp buzzer. I have changed the impeller, flushed the engine to make sure there were no plugs, completely removed the thermostat and then last night changed the head gasket. I ran it for a half an hour last night after changing the head gasket assuming I had fixed the problem (usually it goes off after 5-10 mins). But as we were coming back to the launch, it went off again! It only happens at WOT, haven't had it go off at slower speeds. Anybody have any ideas??? I am going to drop the bottom end again this weekend and look for bad gaskets around the water pump, but is there anything else I can look for?

 

[Mark42]

Re: Overheating......Again!

Have you checked the wire for a short to ground? That will make the alarm sound. Also, when the alarm sounds, have you put your hand on the powerhead to check the temperature by feel? Generally speaking, it should not burn to hold the head for a count of 10 or so.

It might be a good idea to change the temp sensor, just to ensure that it is not the problem.

I guess you could test your temp sensor by putting it in a pot on the stove. Heat up gradually and test with an electric testor to see when the sensor closes. Use a thermometer to test the water temperature.

Another condition that will make an o/b run hot is not enough oil in the gas/oil mix. The friction increases and the motor runs hot.

 

[gregmsr]

Re: Overheating......Again!

Find out what normal operating temp is, when buzzer goes off, check with heat gun.

 

[scottie]

Re: Overheating......Again!

no, I am pretty sure it is overheating, I can smell and feel the heat - more than a car engine at 100 degrees C!

 

[scottie]

Re: Overheating......Again!

BTW - one more thing - my impeller housing doesn't have a discharge tube, but parts breakdown doesn't list one? Is it supposed to? Woould installing one help?

 

[QuadManiac]

Re: Overheating......Again!

Not difficult to add a water pressure and a head temp gauge... about $20 each from Sporqster.com - give you some real numbers to deal with, instead of an 'idiot light' buzzer.