35hp merc. water from side bolt and spark plugs

[keg]

I have a 1987 35hp merc. that was not sending water through the tell tale hole. I change the water pump and impeller (very bad shape), now I have water not only flowing strong from the tell tale but also from the lower unit side bolts and around the spark plugs. I don't know if this is normal or if it could mean bigger problems, blown head for instance. The motor may have been over heated on last trip out but I am not sure, I let a friend take his son fishing and he is not admitting anything. This is my first post so I hope I did it right

 

[rolmops]

Re: 35hp merc. water from side bolt and spark plugs

Hello.<br />Sure sounds scary.<br />Does the engine sound normal in spite of all of the described?<br />It could just be a loose hookup between the water pump and the cylinder housing.<br />Maybe you can check that out and hope for the best.

 

[oldboat1]

Re: 35hp merc. water from side bolt and spark plugs

agree -- scary is the word. But look for the simple stuff first. I would think there shouldn't be water coming out of the plug holes if the plugs are properly tight, even if there is water in there trying to get out. More likely, it would blow out the head gasket and come out on the side of the the head. There are water passages in the head/head cover, as you probably know, so that may be where the water is coming from -- and probably is. On the positive side, it seems pretty clear that the pump is putting water up to the head, so the lower unit leak may simply require tightening the bolts.

 

[keg]

Re: 35hp merc. water from side bolt and spark plugs

Thanks for the come-back. The engine sounds normal when it is running. I really don't understand how the the water is moved through the engine...I'm kinda new at this stuff. I know there is a water jacket around the plugs I was going to look at that. I hate to ask a dumb question but does the middle part of the motor fill with water or just move around the top of the power unit for cooling? When I had the lower unit off it felt like the water tube from the pump was tight up top. Thanks again any advice is appreciated.

 

[oldboat1]

Re: 35hp merc. water from side bolt and spark plugs

Water flows up from the water pump through the water tube you identified, up through the exhaust port water passages, into and through the cylinder head water passages, and out through the exhaust (and tell-tale if there is one). There will be a lot of exhaust water in the upper leg (the housing you looked up into when you saw the water tube going into the engine). If you pull off the head cover and look into the passages, you will see that the water circulates quite completely around the cylinders through the special water passages. You can also take off the exhaust port cover to check and observe the water passages there. Water is always separate from combustion chambers -- that's what the passages are about.<br /><br />You might find that tightening the cylinder head bolts will stop the water leak up there. Don't overdo it -- don't want to break off a bolt. Snug up the bolts in sequence, generally moving from side to side and top to bottom to avoid warping the head. Start with the middle bolts -- best to make a couple of passes rather than fully tightening each bolt in the first pass.

 

[keg]

Re: 35hp merc. water from side bolt and spark plugs

Hey Oldboat thanks again I have looked from cover to cover in Clymer Shop Manual for that info. I am on my way out to the lake now I'll either get it running or spend the weekend on the dock drinking beer and pouting. Thanks again. Brad aka:keg

 

[oldboat1]

Re: 35hp merc. water from side bolt and spark plugs

Well, that strikes me as the right attitude. A few beers by the lake, and maybe a little complaining, ain't such a bad option. (Clymer manuals sometimes begin to make more sense after a couple of beers too.) Take it over to Gun Lake. There's too much weekend boat traffic to get on there anyway -- and all the wakes will push a stalled boat to shore if you do get on.<br /><br />Hey -- Good luck. Let us know how it goes.

 

[harrison20002]

Re: 35hp merc. water from side bolt and spark plugs

oldboat1 has good advice. If you tighten the head bolts make sure motor is warmed up. Hal

 

[keg]

Re: 35hp merc. water from side bolt and spark plugs

Hey good news I changed the gasket around the spark plugs (water jacket maybe) and it fixed the leak around the plugs. I am still getting water from the side bolts on the lower unit and their as tight as I can get them. The motor is running great, the fish are biting like crazy and the local beer store never runs out of Budwieser... I am a happy man. Thanks for all the advise, I am sure I will come up with some other stupid questions in the future. THIS SITE IS WAY COOL. By the way Oldboat, how does a guy in Maryland know about Gun Lake? I have a little place on a small private lake about five miles west of there.Thanks again, Brad