YSB8 Engine Failure

[Rowbearde]

Our YSB8, auxillary for a 1978 Ericson 27, overheated and failed after ~15 minutes of operation. Removal of engine cover released billows of blue smoke which quickly dissipated. Immediately prior to failure exhaust began to discharge gobs of gooey, smelly oil. Engine and transmission levels were checked and found to be topped up. Upon return to marina, engine could be restarted, but would only idle, not rev up. Local mechanics discovered significant bacterial sludge in the fuel tank and it was professionally cleaned along with all elements of the fuel delivery system. Engine was started, but still would not rev up. Engine fuel systems were cleaned again with no improvement. Engine would run at idle and after ~15 minutes it quit and will no longer start.

In addition to the above, it should be noted that for the past few years the oil pressure would illuminate intermittantly during engine operation regardless of rpm and might or might not go out prior to engine shut down.

How can this engine, located on the BohemiaRiver in the upper Chesapeake Bay be diagnosed and repaired?

[Boracay]

It sounds like your engine is old and well worn.

When you add up the costs on a total overhaul (sound like one is needed) a repower may make more sense.

Deciding early could save money.

Don't forget-with a repower everything engine related is new.

[Chief Engineer]

When you refer to all components of fuel system being cleaned I am assuming that tank, lines, lift pump, injection pump high pressure line and injector was cleaned and or rebuilt.

My concern is engine overheating....does not cause fuel problems.....was there any smoke from the exhaust...if so what color was it?

I work on vessels on the Chesapeake Bay and I, for one, would look at the engine before looking at the fuel system.

Keep in touch

Originally Posted by Rowbearde

Our YSB8, auxillary for a 1978 Ericson 27, overheated and failed after ~15 minutes of operation. Removal of engine cover released billows of blue smoke which quickly dissipated. Immediately prior to failure exhaust began to discharge gobs of gooey, smelly oil. Engine and transmission levels were checked and found to be topped up. Upon return to marina, engine could be restarted, but would only idle, not rev up. Local mechanics discovered significant bacterial sludge in the fuel tank and it was professionally cleaned along with all elements of the fuel delivery system. Engine was started, but still would not rev up. Engine fuel systems were cleaned again with no improvement. Engine would run at idle and after ~15 minutes it quit and will no longer start.

In addition to the above, it should be noted that for the past few years the oil pressure would illuminate intermittantly during engine operation regardless of rpm and might or might not go out prior to engine shut down.

How can this engine, located on the BohemiaRiver in the upper Chesapeake Bay be diagnosed and repaired?

[jscott]

Sounds like some or all of the pistons are now siezed, as above engine overheating occured.

Look for plugged cooling passages.

I take it the cooling system has been checked and is operable.

[S/V Antares]

I would put money on the exhaust elbow being clogged where the water injection occures. Restrictions on the water will cause overheating and restrictions on the exhaust flow will not allow rpm. This is a very robust little engine. Do not give up easly.

[Cal25MK2]

You can find Yanmar YSB8 and YM engine repair manuals and operators manuals and a complete parts list with diagrams at sailboatpower.com