Mercruiser 4.3,water in cylinder

[enterprise]

Just started new season!
Mercruiser 4.3L engine 1992 .
New manifolds & rissers+new exhaust shutters fitted over winter.
Ran fine after startup, no leaks, torqued correctly, water emerges from exhaust ports on tansom ok.
No signs of problems
Used for Approx 5 hours, planed ok, no problems.

Took too many heavy friends out over whitsun (at same time).
Couldnt get on plane!
Throttled back, pottered around bay.

Light load next day couldnt get on plane!!!!!
Rattle sound from port side!!!!
Removed plugs, found water droplets on port center plug.

What happened?
What could be the rattle?
Could it be a Misfire?
or is it more serious?

Engine runs fine whilst not under load, but we aint going nowhere fast.

Engine now in very good hands.

Morall support required.

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[DavidP]

Hi

This may be the cause if you have done this.

Caution : Do not race engine before turning ignition key off nor turn key off with engine running above idle. This could cause water to be drawn into engine via the exhaust system and result in internal damage.

Paragraph taken from my Searay Owners manual

Dave.

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[Solitaire]

I think we both need moral support/forums/images/icons/frown.gif I have/had a V8 VP in my boat. Similar situation, could not get on the plane, loss of power and problem starting. The result is water in the bores and hydrolic lock. Like you I had new risers but it looks like new engine now. I suggest you take the oil filler cap off (if you have not done so already) and look inside - if engine oil is white and looking like soft putty then its probably the head gasket gone. Unless you have taken the plugs out and filled the bores full of oil, you have a major problem. Just like me! I've decided to put a new engine and stern drive on. Expensive in the short term but you just don't know whats going to happen next. Whatever action, it ain't going to be cheap/forums/images/icons/frown.gif We can cry into our beer together.

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[Solitaire]

I think we both need moral support/forums/images/icons/frown.gif I have/had a V8 VP in my boat. Similar situation, could not get on the plane, loss of power and problem starting. The result is water in the bores and hydrolic lock. Like you I had new risers but it looks like new engine now. I suggest you take the oil filler cap off (if you have not done so already) and look inside - if engine oil is white and looking like soft putty then its probably the head gasket gone. Unless you have taken the plugs out and filled the bores full of oil, you have a major problem. Just like me! I've decided to put a new engine and stern drive on. Expensive in the short term but you just don't know whats going to happen next. Whatever action, it ain't going to be cheap/forums/images/icons/frown.gif We can cry into our beer together.

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[enterprise]

Thanks solitare for reply but here is more info:

The engine oil is ok! and there are only minute droplets of water in port side center cylinder.
Could it be condensation?

I maybe jumping the gun but have requested info on diesel engines from a place called samurai diesels.
These are bassed in Setton,Devon.
They can supply a V8 GMC diesel,rebuilt 6.2 litre for around £3000 + £1800 for marine kit (including stainless exhaust manifolds)
The engine being GMC bolts straight in!
Trouble is the torque produced would wreck my current alpha1 G2 drive.
So a recon petrol maybe my only option.

Will keep you posted.

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[Solitaire]

Beware! I have heard all sorts of reports about Samuari. Most of them V. unfavorable. Check other postings particularly on the MoBo forum. You could look at a VP Kad 32 diesel or a Merc, but not much change out of £15k. I looked at a new Yanmar 240 hp turbo with Bravo 3 leg - £15-£20k! It depends how old your boat is, and how long you plan on keeping it. Good luck anyway.
I'm not a mechanic so I can't add anymore to your problem, but the water on the plugs may well be just condensation, but I would not have thought that this would have prevented you getting up on the plane.

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