1987 88 spl running hot

[crabbydad]

first time i started engine on muffs this year, overheat alarm went off. was fine when i winterized it last year. pulled thermostats and changed them. still ran hot. pulled hoses off thermostats and ran with longer hoses on to check water flow. plenty of flow and engine ran cool. put hoses back on and engine alarm went off after a few minutes. pulled thermostats off and checked. both are opening up. put garden hose in and flushed. water is coming out of ports at bottom of lower unit, so i assume everything is open. any ideas?

 

[Watermann]

Re: 1987 88 spl running hot

Those hoses are very short, I'm sure you could see if they were obstructed. Did you notice if they were collapsing or kinked at all? Some other things. Did you have the water turned up enough on the garden hose and was the tell tale showing good flow? Sounds like an air pocket is forming on top of one of the power heads. When was the last time you replaced the water pump impeller?

 

[crabbydad]

Re: 1987 88 spl running hot

i bought the engine used, i only had one season on it. there was plenty of water coming out of the hoses on the power head. i am going to put it back together and try it again
thanks

 

[Fleetwin]

Re: 1987 88 spl running hot

Impeller and them poppet valves. Those are located in the thermostat block.

 

[crabbydad]

Re: 1987 88 spl running hot

it was the small hole in the middle that allows water to bleed thru so that the hot water reaches the thermostats. it was clogged up. thanks for the help