Engine problem

[Scotty_Tradewind]

Engine running for a few hours.
Sailed for a couple of hours no engine.
Go to start and it will not turn over passed its compression stroke more than half a turn.

Battery good, plenty of fuel etc.

Turn over engine with decompressor activated for half a dozen turns then release decompressor and she turns over a few times then fires up o.k. as if nothing had been wrong.

The only thing changed this winter has been a new Vetus waterlock about 2feet back from the engine replacing the original as it was looking worse for wear.

Could there have been water getting back via the open exhaust valve whist we were sailing and so got water in a cylinder?
Decompressing would then have let any water pass through and then off she goes with a new intake of diesel. ????

 

[TradewindSailor]

Water in the engine would be my first guess, a dodgy starter motor my second, and bad electrical contact third.

Do you have a photo of the exhaust arrangement. You should have a high rise gooseneck at least 18" above any operational waterline.

 

[oldsaltoz]

Check the engine oil and look for emulsified oil, any water in the oil will show as a cream colour. The costof an oil change is nothing compared to an engine overhaul.

Good luck and fair winds.

 

[Marsupial]

not wanting to teach you suck eggs but you could check that the new water lock is fitted the right way round.

 

[vyv_cox]

The only case I know with any similarities was where the water trap was of insufficient size to take all the water flowing back from the exhaust pipe when the engine was shut down. This was a design fault that affected more than 40 engines in new boats. I am guessing that this is not your problem, as your engine has been installed for some time.

Assuming your new trap is of similar size to the old, and no other changes, i suspect something else. Bad news is that this happened to me on a road vehicle when the cylinder head cracked. Good news is that a dribble of diesel from a slightly fouled injector could do the same and will clear itself up.