High temp alarm on Johnson 88HP?

[windshear]

1988 Johnson 88HP V4 Model# J88MSLCCC (CV4?) engine on a 16' bowrider. Yesterday the OMC remote control (I believe it's also an '88) started a constant buzzing after maybe four minutes of operation. shut the motor off, restarted, again constant buzzer after less than a minute. Pee stream looks okay to me. Just put the boat in the water for the season. I bought this boat three years ago. I have no idea when the water pump/impeller was last replaced (nor have I replaced one). The only thing I did to it this year was change the lower gear oil and replace boat's bilge pump. It ran fine last year. Is this a high temp alarm and if so how do I diagnose it?

 

[tarpstrapp]

Re: High temp alarm on Johnson 88HP?

when you had it running was there also water coming out of the two hole at the back of the engine or just out the little hole on the side

 

[tashasdaddy]

Re: High temp alarm on Johnson 88HP?

Well you are due and water pump service, also the tale tell stream, is just an indicator the water pump is functioning. it does not tell you that the thermostats are opening, and cooling the block. i would check the sending sensor also. but your motor is due for some maintainance.

 

[windshear]

Re: High temp alarm on Johnson 88HP?

Tarpstrapp, water came out of the prop exhaust , is that what you meant?
Will the owners manual tell me how to replace water pump, check thermostats and sending sensor? Or do I need a service manual?

 

[windshear]

Re: High temp alarm on Johnson 88HP?

I replaced the thermostats and poppets, still overheats same way. next I will do the impeller and probably pull the heads off, check the water paths and deflectors. Does this sound like the correct approach?

 

[tashasdaddy]

Re: High temp alarm on Johnson 88HP?

i would have started with the impeller. do one thing at a time.