Exhaust shutters

[77GlastronMT]

On my '77 MC 165 the intake and exhaust manifold are combined, at the aft end there is a "riser" that comes off the manifold does a 180* and connects to the bellows (I think). My question is; is that where the shutters are located? I'm getting water in the oil and want to check that first. If they are all there and intact does that mean they are probably ok? My second step would be to pull the manifold and leak check it, 3rd would be pull head. Boating season is here and I've put this off too long!! Thanks.

 

[Bt Doctur]

exaust shutters would not normally allow water into the oil. I would drain the manifold and riser first. Then remove the riser checking for any wetness indicating a leak. That could foul #6 plug and could allow water to enter from #6 cylinder. Then pull the manifold, again looking for any wetness in the intake and exaust ports.
How was it winterized, who winterized it?. Was it ever overheated ?

 

[alldodge]

Agree with BT Doc, you have a crack somewhere and may need an engine

 

[77GlastronMT]

I bought the boat cheap last summer, long story short, found out it needed a lower drive. I've only ran it on the muffs, it ran good but it did have water in the oil. Someone told me that if the exhaust shutters were damaged or gone the water could run up into the manifold and through any open exhaust valves. I pulled the plugs and they all looked ok. I had changed the oil just before I ran it, only ran it for 5 maybe 10 minutes and had water in the oil. I don't know how long the water was running while the engine was off. This was all done last fall. I just found a used lower drive I could afford and am trying to get it in the water this summer. This is my first boat, I don't know if I'll like boating (or can even afford it) so I'm trying to do this on the cheap.

 

[duped]

Hate to break it to ya, but if you get water in the oil after 5 or 10 minutes on the muffs, you most certainly have a serious problem, likely a cracked block from freeze damage. The exhaust flappers have no effect when the boat is not in the water, so start looking elsewhere. Check for any cracks on the outside of the block and manfold (s) If you see any on the outside, you can bet there's an internal crack that's causing your oil problems. Was it winterized last year?

 

[77GlastronMT]

I winterized it, i pulled the plug out of the exhaust manifold, front part of the block and opened the drain valve on the back half of the block, put fuel stablizer in the tank and fogged the carb. No cracks on the exterior of the block, looks brand new. I'm gonna pull the exhaust manifold and check it first, then head if necessary. I had water in the oil before the winter though so it could've been from last winter with the old owner.

 

[Sangster21]

I am having a water in oil situation with the same engine. I seem to be losing coolant and pulled plugs to find #6 wet. I am going to have the head checked to see if there is a crack that is allowing water (coolant ) to get into the combustion chamber. I don't think you would have an issue with the exhaust shutter causing problems on the muffs, I believe it can be an issue out on the water as a following wave can push water up the exhaust and into the manifold, but that is not possible on dry land.