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KK4AMI
06-05-2012, 04:32 PM
I have a little 4 CYL Series BT250 marine engine that is smoking on me. It only smokes while warming up and when at idle. When I'm running at speed it seems pretty clean. The smoke is sort of a bluish white. I only have 388 hrs on the engine, but it is 11 years old. I'm thinking its an injector issue. Thanks for any help.

KC2UGV
06-05-2012, 04:36 PM
Check your glow plugs and air filter. I know a crap air filter caused white smoke from a 5 ton truck before (Cummins Diesels). Burnt glowplugs do it too. And, they're both easy to check.

N8YX
06-05-2012, 04:37 PM
Bluish white sounds like burning oil, and black would be excessive fuel...right?

Have a pyrometer with which you can measure the EGT at idle? This might indicate an overly "lean" condition whereby the engine is also burning some of the lubricating oil - and I'm assuming it's normally aspirated...

Ah, WTF do I know about these things. I just know how to tune gas EFI mo'sickle engines.

ETA:

Corey may be onto something with the filter aspect.

KK4AMI
06-05-2012, 04:59 PM
Thanks guys, it is turbocharged. The filter is a possibility. But not much dust on the Chesapeake. Also I don't have glowplugs. If I need glow plugs, it is too cold to fish :)

N8YX
06-05-2012, 05:28 PM
Thanks guys, it is turbocharged. The filter is a possibility. But not much dust on the Chesapeake. Also I don't have glowplugs. If I need glow plugs, it is too cold to fish :)
Three things, then:

1) Compression check and compare cylinders against "normal" readings;
2) If the reading in Step 1 is near normal: How much lubricating oil does the engine burn - more than usual, or not?
3) If the turbo oil supply separate from the engine? If so, is it consuming oil?

PA5COR
06-05-2012, 06:06 PM
Blueish white smoke is possibly unburned fuel particles from incomplete burning the fuel.
Looking at your problem the timing of the moment the fuel is injected might be off, too late .
That will cause the fuel to not burn up completely and condensate to white smoke with the blue from the particles tht did burn in the process.

KK4AMI
06-05-2012, 06:16 PM
Thanks again Guys. I've been checking some of the diesel websites. You are all right on the money.
1. Check Air Filter
2. Check for oil consumption
3. Check timing

Those are cheap things I can do before I hand it over to the Marina Mechanic and he claims my soul!

WØTKX
06-05-2012, 06:19 PM
Too late. :sadwave:

Cars are just a hole in the road to pour money into.
Boats are a dynamic sucking vortex for your cash.

Except for that aluminum canoe I used to have.
Actually made money on it when I sold it.

W5GA
06-05-2012, 09:44 PM
Boats are a dynamic sucking vortex for your cash.
Boat is an acronym for break out another thousand.