Another engine question....

[Swamp Monster]

Allright, got the 40 merc started no problem on Saturday using the muffs. It did not seem like it was pumping water at all so I did not run it for more than a few seconds at a time. No problem as I plan to have the impeller and if needed the water pump replaced. Problem was that I had water coming out at the spark plugs. Not a lot, but enough to concern me. Have never seen this before with an outboard. Pulled each plug individually and fired the motor to see if it would spit water but it didn't, but there was gas and oil like there should be. Plugs looked great. I tried it again with all the plugs installed and it was still spitting water out the plugs after the engine had run about 10 seconds. I shut it down and left it at that.
Do I have serious problems or is that a by product of the waterpump/impeller not working? Someone told me that may be the case but had never heard of such a thing so I don't know. The engine sat for about 18 months so I though maybe it's just condensation. It's going in the shop soon to change the impeller and lower unit oil and some other things (fast idle doesn't work and an oil line needs to be replaced) and I would like to have a general idea about this problem before I get taken to the cleaners!

Thanks!

[waterfoul]

Sounds like the water jacket gasket is failing. The water is (more than likely) NOT coming from the spark plug hole itself, but from the water jacket that surrounds the top of the head. My 50 merc did this. Simply take the jacket off and replace the gasket.

[FREEPOP]

I can't remember what I last charged to change the impeller, it was around $150, parts included. It's not a tough job and if you were closer, I'd pick it up and do it for you.

[waterfoul]

Check this link. Part #34 is the cover I'm talking about. If you remove it, scrape off any old gasket material from the cover and the block, and then use a high temp gasket material (the orange stuff is what I used) to seal it back up you will be golden.

http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=%2090627&ivar=images/MERMAR/90627/21.png&inbr=673&bnbr=110&bdesc=CYLINDER+BLOCK+CRANKCASE+AND+COVERS

[Swamp Monster]

Boy, when you mention gaskets that makes me nervous.... I'm almost positive it was coming directly out of the plugs, but maybe tonight I'll try it again and look at it closer. It had me a little jumpy to be honest so I didn't hang around long....wanted to shut it down quick. I have some mechanical aptitude but very limited experience with outboards so I'm extremely gun shy. :16suspect
I'll let a professional handle it, I just wante some idea of the problem so a dummy like me doesn't get taken advantage of. I trust our local marina, they do a pretty good job. I've been buying all my stuff there when I know I can get it somewhere else cheaper but they've been very helpful. He quoted me $120ish or so to change the lower unit oil and impeller which is more than fair from what I've heard. Double that for chinging out an oil line and messing with the fast idle I'd guess. Don't know about this water issue.

[waterfoul]

If you stop and think about it... it's nearly impossible for water to get into the combustion chamber. If it did the motor more than likely wouldn't run.. it would hydrolock (water doesn't compress) and you would be bending rods and breaking crank shafts. Plus, pushing water past a spark plug would be next to impossilbe... too many fine threads. I think you will find that the water is indeed coming from the jacket... when I had this issue I would have SWORN it was coming out of the plug hole... until my buddy and Merc guru came over and showed me what was up. Took us about a half hour to fix.

[Swamp Monster]

If you stop and think about it... it's nearly impossible for water to get into the combustion chamber. If it did the motor more than likely wouldn't run.. it would hydrolock (water doesn't compress) and you would be bending rods and breaking crank shafts. Plus, pushing water past a spark plug would be next to impossilbe... too many fine threads. I think you will find that the water is indeed coming from the jacket... when I had this issue I would have SWORN it was coming out of the plug hole... until my buddy and Merc guru came over and showed me what was up. Took us about a half hour to fix.



Yeah, Hydrolocking the motor was what put me in panick mode, but when nothing came out when I removed the plugs individualy I was stumped. I'm sure your right....at least my wallet hopes so!:tdo12:

[TONGA]

Yea what waterfoul said ,,I have seen a lot of those gaskets go bad.

[black max]

this is a common problem, your motor is leaking around the water jacket on the back of the cylinder block, this is a blind cylinder and has no removable head. this usually occurs from a over heat. i would pull the water jacket off scrape the old gasket off and put a straight edge over the block and check the cover making sure its not warped. i would use yamaha bond or gel seal to install the new gasket, and torque the bolts to mercurys spec, make sure to check your water pump also.

[Swamp Monster]

Thanks guys! The price of the cover (per the link) isn't bad, but hopefully it's not a sign of a more serious problem.

[waterfoul]

What year is your motor anyway? Mine is a 1972 and it took nearly 30 years for my gasket to start leaking... but once it did it was like someone turned on a faucet ever time I ran the thing.

[Swamp Monster]

1997 I believe.

:tdo12: