Boats with Re-built motors...What to Think?

[deluxe68]

Originally Posted by brianlara 3

Yes all round. But many owners rarely give their engines a good fanging to blow the cobwebs (carbon, sulphates, varnish , moisture) away.
Constantly charging the batteries at 1200 revs with no load kills engines.
And very few boats have alternators so powerful as to be considered a load. Very few!!
You can tell 'em but you can't change 'em.
For whatever reason, people seem reluctant to drop the mooring and go for a good run.
God knows?

I used to work in a facilities department and we had about 15 building sized generators. I talked to the Caterpiller (and other companies) mechanics about run time and engine life. Before I started in the department we ran each engine unloaded for 30 minutes a month. The first time we ran one under full load it barfed and needed $20k in repairs. The mechanic said that a local hospital had 5 gens in one building and all 5 blew up during an outage. The cause was wet stacking, they never got the exhaust hot enough and for long enough to burn off the soot buildup. We started doing annual load banks and never had another problem. The exhaust temp is monitored and the engines are run under load for several hours at least. The mechanics also said that every time you start the engine it should warm up to operating temp before any load, it should run for at least 15 minutes at temp and then run 15 minutes at idle to cool down. I noticed that my boatyard does not warm engines up before operation, you would think they would know better.

[lifeofreilly57]

Originally Posted by deluxe68

I used to work in a facilities department and we had about 15 building sized generators. I talked to the Caterpiller (and other companies) mechanics about run time and engine life. Before I started in the department we ran each engine unloaded for 30 minutes a month. The first time we ran one under full load it barfed and needed $20k in repairs. The mechanic said that a local hospital had 5 gens in one building and all 5 blew up during an outage. The cause was wet stacking, they never got the exhaust hot enough and for long enough to burn off the soot buildup. We started doing annual load banks and never had another problem. The exhaust temp is monitored and the engines are run under load for several hours at least. The mechanics also said that every time you start the engine it should warm up to operating temp before any load, it should run for at least 15 minutes at temp and then run 15 minutes at idle to cool down. I noticed that my boatyard does not warm engines up before operation, you would think they would know better.

Excellent advice, diesels run much better under load, they don't respond well when lightly loaded.
They also like being run to full temperature for a good amount of time, if not, and your engine isn't run for extended periods, as in many race boats that only use them to get to and from the dock, you should think of changing your oil more often to get rid of the moisture and contaminants that aren't getting burnt off. Still won't help with carbon buildup though.