1990 Evirude 120 overheats.

[ALLAPP]

This engine runs fine at high rpms. the temp is fine.Run at a 1000rpm for 15 minuets and it dies.the temp is out of site and no signal is sounded. wait for it to cool off and runs great at high rpms. does it need a water pump kit?

 

[Walker]

Re: 1990 Evirude 120 overheats.

Sure sounds like thermostats. At higher rpm's increased water pressure push the bypass valves open to allow almost unrestricted water flow through the cooling system. At low rpm's the valves are closed and water must go through the thermostats. I do believe on your particular motor that the thermostats are set against a spring and the entire thermostat assembly acts as the bypass.

 

[Gary85_]

Re: 1990 Evirude 120 overheats.

How much water is it moving at lower rpm? Noticable difference? <br /><br />I don't pretend to know what I am talking about but.... I would say pump.

 

[rodbolt]

Re: 1990 Evirude 120 overheats.

describe the t-stat housings. do they have a small water hose running from each housing or are the housings rather flat with no water tubes. and when was the last pump overhaul.

 

[ALLAPP]

Re: 1990 Evirude 120 overheats.

The t's have never been changed so will give it a shot. If that doesn't work we will change the water pump and see what happens. thanks for the inputs.

 

[ALLAPP]

Re: 1990 Evirude 120 overheats.

Why does the engine quit? shouldn't an alarm go off before that happens.