What happens when salt...

is staring you in the face and is concentrated around your head gasket?
I have a Evinrude 175 1993 and went to change the plugs and noticed there is about 1/16" of salt caked around my starboard side cylinder head, concentrated on the head gasket, all the way around, anywhere from 1/4" to 1/2" wide. the other side is perfect, no rust or salt. so now i am thinking i have a blown head gasket on one side which is fowling my starboard side and causing the extreme misfire and poor running.

anyone have in thoughts on this????


Long version:

Evinrude 175 1993, just ran an entire tank of mexico gas through the engine, no problems, this is all off US pump gas. however, ran the tank dry on Mex gas for the first time, so maybe a bunch of crud got picked up and put in the engine...?

took out the boat over the weekend, ran 4000rpm for about 20 minutes, four guys , no issues. then it felt like i hit something the engine misfired so bad. so i stopped, checked it out, no issues, tried to turn it back on and that is when it started to get interesting. i have never seen anything misfire so bad in my life and i thought my engine was going to shake off my transom. after trying for a while, thought i might have some bad gas, or maybe my fuel/water seperator was full so i pulled it off and drained it and put it back on. took about 1 hour to get started, then it ran, but had some moments of worry when it misfired and the rpm's lowered a lot, then it would pick itself back up and run perfect. fished 6 hours, ran in, no problems.

next day, same thing, ran good, took a dump after about 20 min, hard starting extream misfiring, ran fine all the way home???

so i was thinking fuel contamination and was going to do new plugs, new filter/water seperator and run some iso-heet to make sure.

went to change the plugs and noticed there is about 1/16" of salt caked around my starboard side cylinder head, all the way around, anywhere from 1/4" to 1/2" wide. the other side is perfect, no rust or salt. so now i am thinking i have a blown head gasket on one side which is fowling my starboard side and causing the extream misfire and poor running.

anyone have in thoughts on this????

next step is to check compression one side Vs. the other. but is this just an obviously blown head gasket? if i were to change one side, should the other side be changed for good measure?

Re: What happens when salt...

That salt stuff you are looking at really isn't that unusual. Aside from the anxiety it causes, it probably isn't a problem. That is not to say that you don't have a blown head gasket, but that is another story.

From your story, it sounds like you have something wrong far more serious than the gas and plugs stuff you are looking at. You are correct in doing a compression check as a first step. I believe the results will point you to where you need to go next. My money is on something came apart inside.

Re: What happens when salt...

Do you think the oxidation was bad enough to comprimise the ground on the spark plug?

Re: What happens when salt...

You have about ten head bolt's that should rule out the ground problem.

Update: Salt around head gasket = bad(duh)

Update: Salt around head gasket = bad(duh)

well that tow in from 10 miles out confirms that changing the plugs and fuel filter did not help.

same issue, run for 20 minutes then die. this time white smoke; which really means head gasket to me, especially with the port side deposits of salt around the gasket and the heavy misfiring.

Will do compression in the PM tomorrow.

I can see the head gasket and i am not afraid to change it, but what are my concerns? or do i not know until i pull the head off and look at the head, pistons etc...

Thanks again for the help.

Re: Update: Salt around head gasket = bad(duh)

Re: Update: Salt around head gasket = bad(duh)

Not sure if this will help you or not, but I had a similar bead of what looked like salt around both of my riser/manifold flanges and pulled the risers assuming I would find bad gaskets, corrosion, etc. but both the castings and the gaskets were virtually like brand new with no evidence of leakage. I suspect some weird form of electrolysis that I cannot explain. Your run problem may be unrelated to the salt residue and would explore all other possibilities before pulling the head.