Blown head gasket??

[Saint Paul Dan]

Just checking if anyone has any suggestions or input regarding an issue I encountered... I own a 1992 50hp Evinrude 2 stroke which has been running like normal this year-somewhat ruff during slow speeds but smooths out after increasing throttle a little.

The other day I started it up for the 3rd time that day and slowly accelerated as usual. About 2 minutes after reaching maximum speed, my motor seemed to let up a little. I was running in 20ft of water or more, but I initially thought I made contact with the bottom so I let off my throttle and raised my trim. Before I could put my engine in neutral, I heard a small burst which was followed by a lot of white smoke. I quickly shut off my motor and have not attempted to even start it since this occured. I assumed this was a sign of a blown head gasket, but this is my first boat and motor so I'm still a bit clueless.

Any Ideas? I appreciate any input that anyone has...

Thank you,

Dan

[marine_man]

It sounds like that's a possibility... I'd start with a compression check... even if it's the thumb over the spark plug hole to get a feel for which cylinder (s) have issues.

marine_man

[Eric Wettschreck]

This isn't uncommon on these motors. MM is right, do a compression check. You don't really need to hook up a gauge, just put your thumb over the plug hole and if you have a blown gasket it will let you know pretty quickly.

The good news with this is a head gasket is a fairly easy and inexpensive fix. If you're halfway mechanically inclined it should be no problem. If you pull the head, put a straight edge all over it. If there is even a small amount of warp take it to a machine shop and have it shaved. Once again, not an expensive thing to have done.

If the head gasket is the problem you have to ask yourself why it blew. It's normally an overheating thing. Water pump or thermostat going bad??? Possible intake gasket leaking??? When it's running, do you hear a whine or whistle? If so, I'd also be looking at the intake gasket. For the most part gaskets don't just blow. Age will take it's toll but with a head gasket there is normally something else happening that made it go. And normally it's excessive heat.

[boatfixer]

Yup what they said.

If its blown you will more than likely find water on the spark plugs to. Easy to distinguish, just slap the plug into the palm of your hand and the water will bead, gas wont.

[Saint Paul Dan]

So if I understand it crrectly, I should:

1) Determine if the head gasket is blown by doing a compression test

2) If head gasket is blown, there most likely is another issue that contributed to the blown gasket... So, determine probem that caused blown gasket which is most likely related to overheating.

3) replace head gasket and any additional parts that contributed to blown gasket

Thank you guys very much for the help.

Dan

[marine_man]

That's the approach I'd take...

marine_man