89 175 Johnson water leak

[stilflotin]

I have an '89 175 Johnson which I started for the 1st time this morning. At the very base of the power head on the port side I noticed water leaking from a small (approx. 2 X 3 mm) rectangular hole. Does anyone know what this is and what I need to do to fix it?
Many Thanks

 

[emdsapmgr]

Re: 89 175 Johnson water leak

These comments reference an 83 2.6 Johnson, the predecessor to your 89 175. You may be referring to a small tapered round hole on the rear port side of the exhaust adapter. The factory likely drilled some special hole into the interior of the exhaust adapter, then had to cap the hole for normal engine operation. The factory sealed that hole with an aluminum tapered plug which was permanently secured into the adapter. It is possible for that plug to come out. Esp, if some water remained inside that adapter over the winter. It is possible that expanding ice forced the plug out of it's hole. Likely the plug has fallen down into the lower cowling area. You need to find it. That special plug is not shown in any parts diagrams. It can be re-secured in place. Put some red loctite on it and lightly tap it in place with a small hammer. Let it dry for a day prior to restarting the engine. Keep an eye on it each spring when you first start the engine.

 

[stilflotin]

Re: 89 175 Johnson water leak

Thanks Admiral. It's not a round or oval plug though! It appears to be a small machined area right at the bottom surface of the power head where it bolts to the Exhaust Housing Adapter.

 

[emdsapmgr]

Re: 89 175 Johnson water leak

Can you post a picture?

 

[stilflotin]

Re: 89 175 Johnson water leak

Picture is attached.
Thanks,
DA

 

[emdsapmgr]

Re: 89 175 Johnson water leak

That small hole is at the bottom of the inner exhaust manifold. Where the flat manifold bottom mates to the top of the exhaust adapter. Usually there is nothing coming out of that area. There is a figure 8 (or rectangular) oring that nests in a groove in the exhaust adapter and compresses under the inner exhaust manifold when the powerhead is tightened/bolted down. Usually, if that oring deteriorates (due to heat) you can get a small amount of black, oily exhaust residue out of that area. Unusual for water to come out. It is possible that you have a leak at the inner exhaust manifold gasket and it is coming out of that hole. Do you have any signs of water in the powerhead? Do any of the spark plugs appear washed-esp the two lower ones? Do the bottom two piston tops look different from the top 4? [I see that plug, mentioned in my prior post-hiding behind the lower cowling latch.]

 

[stilflotin]

Re: 89 175 Johnson water leak

Thanks again. I'm on a business trip this week and will take a closer look this weekend.
Regards,
DA

 

[stilflotin]

Re: 89 175 Johnson water leak

emdsapmgr,
Thanks, you were right. It was a small o-ring broken between the block and the exhaust housing. It took me while, as when I pulled apart the back end of the Johnson there were some other surprises. Long story short, she's back in the water and running great - no water leaks either!
Thanks again,
DA