1984 90hp Evinrude water pump question

[DLMcBeath]

I just bought a boat with a 1984 90hp Evinrude. When the seller ran it for me he used muffs. I noticed no water coming from the "pee hole" there was water mist coming from the exhaust. I asked him about overheating, he said he hadn't had any issues with overheating. There were no signs of overheating. I'm not familure with this model. Now for my questions,

1) I read somewhere that sometimes water doesn't come out of the pee hole when using muffs. Is that true?
2) I take it there's a thermostat on this motor, if so when should it open? We didn't run the motor long, maybe 5 minutes.

Thanks

 

[Joe Reeves]

Re: 1984 90hp Evinrude water pump question

When a high horsepower engine (yours) is running on a flushette, the water pressure must be turned on full blast.

The plastic water outlet might be clogged somewhat. Try cleaning it out with a piece of wire when the engine's running. Even on a flushette, water should shoot out that plastic telltale water outlet with great force.

The engine has two thermostats and two water bypass walve assemblies, located in the housing between the cylinder heads at the bottom portion of the powerhead.... hoses connected to heads leads to thermostat housing.

The thermostats open at approximately 143 degrees or so. When they open, water will flow out the holes/slots that exist just over the cavitation plate (plate just over the propeller) at the rear portion of the lower unit. If cold water flows out immediately when the engine starts running, the thermostats are either missing or stuck open.

 

[DLMcBeath]

Re: 1984 90hp Evinrude water pump question

Thanks Joe,

I got this boat pretty cheap, I think I'm gonna take it to the shop and get it checked out. It won't hurt to bad to put few bucks in the motor just to be safe.

 

[DLMcBeath]

Re: 1984 90hp Evinrude water pump question

After further investigation, the tip of the tell-tale was blocked, after I cleared it water shot out like expected. Motor still feels pretty hot. I'll probably still take it to the shop and have them go over the motor.

 

[Joe Reeves]

Re: 1984 90hp Evinrude water pump question

Like I said, the thermostats open at about 143 degrees so the powerhead will feel pretty warm, actually too hot to hold your hand on either head for more than a few seconds. It's important that both heads feel the same to assure that both thermostats are functioning normally.

That model has a overheat warning horn. It should beep just once when you turn the key to the ON position. If it does not, find out why. You can test the horn by (engine not running) having the key in the ON position, then ground out either TAN (overheat sensor) wire that you'll see protruding from the cylinder heads. That completes the warning horn circuit and the horn should sound... and again, if it does not, find out why as that the only warning you'll receive is the engine overheats.... the second warning actually is when the engine seizes to a screeching halt (too late)!

 

[DLMcBeath]

Re: 1984 90hp Evinrude water pump question

Where's the best place to ground out the wire? I found the wire, but I don't see a bare spot to short the wire.

 

[DLMcBeath]

Re: 1984 90hp Evinrude water pump question

Is there an aftermarket temp gauge that could be installed?

 

[Joe Reeves]

Re: 1984 90hp Evinrude water pump question

Ground it anywhere on the block, scratch a spot if need be. Temp gauges should be available on this site or at any dealership.