westerbeke Gray smoke

. 15kw grey smoke under load any ideas runs good other than that

Is it using any coolant?

Is it smoke or steam? Steam dissipates, smoke lingers.

I think it is smoke. lingers off from the boat for 10 feet or more. As far as using coolant none being used that I can tell.

If the smoke is dense, an oil sample analysis should show if there is something really out of whack. Cheap and fast.

Post a video of it. It sounds like either steam or fuel.

Is there a sheen on the water where the exhaust comes out?

Only happens when you put a load on it? Does the engine/gen seem to work harder now with load than before when loaded?

Initially when you first start it up sometimes you get a sheen but it clears after loading for about 10 minutes or so.

Grey smoke usually indicates a fuel/rack or governor problem. Usually a perforation in the governor's diaphram allowing more fuel to enter the injectors than is burned.
dk

Rogerh said:

Initially when you first start it up sometimes you get a sheen but it clears after loading for about 10 minutes or so.

Click to expand...

Well if there is no sheen at all then it's more likely steam.

It does have a sheen but does seem to clear after running a while but the smoke does not. I will try to get a video tommorrow and post. If it is fuel, how should I troubleshoot to narrow down injector or govenor?

Cheapest is to check each injectors and cylinder by simply loosening the fuel nut on the injectors , one at a time., while underway , under load.

If its only one cylinder , I would yank that injector and have it rebuilt.

After a rebuild IF the smoke stays its compression check time.

If labor is free a compression check first would be informative.

I would also check the engine operating temp as too cool can cause crap combustion , and smoke.

OK, I went out to take the video today of the smoke. Started the gen up and started video, no smoke or sheen at all. Then loaded gen with 4 ACs and still no smoke. Then I let it run for 45 minutes with load up to good operating temp and still no smoke. All is well, I guess I was seeing things. Here is some background of what I did before this.
I changed oil, and flushed coolant, replaced a defective hose from coolant pump to heat exchanger, cleaned heat exchanger with rod through tubes, some clogged a little. Finally replaced zinc and gasket. Now engine running cooler. I did run the gen a number of times through this work with little to no load to check items as I went through the work. ( this might explain some sheen because of not running gen with load for short durations)
After the above work I noticed the smoke after we had been anchored and gen ran all night with little load. 2 ACs on but did not run much after initial cool down of cabin. Cool damp morning. Could it have been a result of warm exhaust water hitting the cooler sea water??? Note it was not very much smoke to start with....
I guess I will monitor and hope I don't see it again.

Some atmospheric conditions favor making the "steam" visible. Cool, still and humid. Sounds like what you had.