Head gasket blown

[ggreen]

The motor is a evinrude 30 hp 1990. I got a call from a mechanic indicating that the impellers on the water pump are melted, needs a complete water pump it. The head gasket is blown (due to heat build up), the pressure in my cylinders is 60 lbs. and that I need a neutral start switch. He indicated that he was unable to get a visual on the piston skirts? He stated that there was no melting of the aluminum.<br />My question is how bad is this? What else could have happened to the engine? The engine shut down while it was running. The lower unit was hot to touch. When the motor shut down it was idling for about 10 min.<br />Thanks in advance for your help.

 

[OBJ]

Re: Head gasket blown

If that's all the wrench can find gg....then I'd say ya' got off pretty lite. Overheat is an engines worst nightmare. Can cause piston scoring, seizure, pistion melt and a bunch more. Probably lucky it was at idle when it happened. The only way you can get a fairly good look at the piston skirts and rings is through the exhuast cover and bypass covers.<br /><br />Hope things work out for ya'...

 

[Walker]

Re: Head gasket blown

Were you running it on dry land. Thats the only way I can imagine the impellor melting.

 

[ggreen]

Re: Head gasket blown

Originally posted by Walker:<br /> Were you running it on dry land. Thats the only way I can imagine the impellor melting.

No, I was in the lower Niagara river. I left the engine in idle as I was fishing a back drift which pushes you out into the main current. I had a bow mount trolling motor which got me back up to the dock.

 

[Paul Moir]

Re: Head gasket blown

You can also pick up a bit of giant kelp (or a plastic bag I suppose) in the middle of the harbour and ruin a good race say last weekend. <br />At 2/3rds throttle, a '79 4hp merc's impeller lasts about five seconds when it's intakes are blocked.<br /><br /><br />Always carry a spare impeller.