water being pumped into the cowling area

[doehunter]

Help!
i have a 2001 model 25 hp merc.
I habitually check my water outlet under the cowl when underway. I noticed yesterday that while the water outlet looked normal, there was water draining from the other side of the cowling also. I took the cowling off and water was pooled up around the engine.
I killed it and let it drain out. Pulled off the hose and blew through it. Put it back on, but left the bottom of the hose off so it could drain outside the engine. When I started it again, the area around the engine filled up with water again. I can't see where it's coming from.
Any ideas?
I put a new water pump on it about 2 months ago but haven't noticed this until yesterday.
Thanks,
Jim

 

[will941s]

Re: water being pumped into the cowling area

The gasket between the powerhead and the midsection is leaking. The midsection mates with a block that mates with the powerhead, and most likely the gasket between that block and the engine has a leak. You can remove the lower coweling and try to tighten the powerhead mounting bolts, maybe a few of them have shaken loose.

 

[Texasmark]

Re: water being pumped into the cowling area

The gasket between the powerhead and the midsection is leaking. The midsection mates with a block that mates with the powerhead, and most likely the gasket between that block and the engine has a leak. You can remove the lower coweling and try to tighten the powerhead mounting bolts, maybe a few of them have shaken loose.

I don't know what size they are but be careful that you don't break one off or strip it out. I think (one bolt at a time) I'd loosen it and snug and do that a couple of times to get the feel of how clean the thread mating is. If you have a lot of friction when doing that, I'd pull the bolts, clean them up and then tighten. A little oil on the threads wouldn't hurt.

While it's out, measure the diameter of the shank and look at the head for 3 or 6 raised radial lines which indicate the strength of the bolt. Say the shank is 1/4 inch and there are 3 lines on it. Get on the www and run a search engine looking for bolt torque specs. You should be able to get a chart and look under 1/4 Grade 5.

You may not have a torque wrench but you can get a feel once you get the number which will be in inch-lbs probably. So if the number is 36 inch-lbs for example, that's 6 lbs of force at the end of a 6 inch wrench, or 3 lbs at the end of a 12" wrench.....which isn't all that much.

I did a lot of blabbing here but I don't know you nor your mechanical aptitude. If all this saved you from stripping out, or breaking off a bolt then it was well worth it. If it was old hat to you then great better safe than sorry.

Mark

 

[will941s]

Re: water being pumped into the cowling area

Texasmark is right, be very very careful. On my 89' merc 25 I had to replace the midsection and stripped 3 out of the 6 bolts.....the bolts themselves are strong, its the aluminum on the powerhead that gives way. There really is'nt a whole lot of thread holding it on, just a long long shaft on the bolt. I took my powerhead off and re-tapped all the bolt holes and installed new slightly oversized bolts with antiseize. So in all, scared the hell out of me when I stripped the threads....but it took no time at all to fix the problem, just a steady slow hand re-tapping. I think the head size on bolts are 5/16 maybe...been awhile.

 

[Texasmark]

Re: water being pumped into the cowling area

I don't doubt his memory as I was just below that with my guess of 1/4". So I went to the www for you and looked up 5/16 - 18 Grade 5 and the torque spec is 17 dry, will safely be about 10 wet (oiled or if you do as he did....apply anti-sieze like is used on spark plug threads) ft-lbs (120 inch-lbs) max. However, just like happened to Will, you can strip the aluminum also and as he told you that is a pain.

So I'd feel comfortable with the numbers I gave you for the 1/4" in my first reply as adequate to hold the joint yet should be light enough to not strip out.

Mark