engine locks up

[Henry Weber]

My YSB-12 (1300hrs) on Hunter 30 starts easily and is reliable. But two days ago it was hard to start. Required 10 sec. of cranking and then barely got going. It appeared to run okay with normal power after it started. Next day after sitting overnight engine locked up solid when I tried to crank. 2nd try same thing. Opened compression release and it cranked okay. Then with release closed, it cranked but started only with great difficulty. When running I did not see any unusual signs such as white or blue smoke. Oil pressure normal,temp normal, discharge water also normal. I would really appreciate any ideas as to what is going on. Thanks.Henry

 

[Pete]

your batteries

check your batteries/charging system and your starter. Sound more like a electrcal issuse then mechancal

 

[Gordon Torresen]

Engine lock-up

Your problem could be a hydrostatic lock caused by water getting into the cylinders. The usual reason is a malfunctioning anti siphon on the cooling water line. This malfunction is usually accompanied by a worn or broken sea water pump impeller. Opening the compression release lets the water out through the exhaust valves.  Water can also get in when an engine is having staring problems. If your engine ever fails to start promptly, the first thing to do is to shut off the sea water cock so that you dont pump in water at cranking speed. (Don't forget to reopen it when the engine starts) The hard starting that could lead to the hydrostatic lock could well start with slow cranking as mentioned in Pete's post.