2gm 20f black smoke

[thetone]

Last summer the Yanmar 2gm20f engine on my 1987 Hunter 28.5 was sending out black smoke and un burnt deisel. My yard said I needed to rebuild the injector pump and replace injectors. That work was completed and the symptoms went away. Unfortunatly the boat dismasted before I could really test it. This year on the first start up it seemed fine, started on the first try with no black smoke. On second start up the exact same symptoms returned, balck smoke unburnt deisel and no power. Does anyone have any suggestions on my next course of action?

 

[kappykaplan]

Have you checked the mixing elbow? I just had a similar problem with my Universal, and cleaning the mixing elbow made a world of difference.

 

[Allan12210]

Make sure the secondary filter is screwed on correctly. My friend's was cockeyed in the canister so it didn't seat right. It poured tons of black smoke until we re-installed it.

 

[thetone]

mixing elbow replaced. she is running like a charm now!

 

[saltygator]

I had the same problem while in the Keys on vacation. Took the mixing elbow apart on the hook, replace all the filters, bleed everything, cleaned the air cleaner. Still blowing black smoke at half throttle and above. Gave up and joined the kids snorkeling. The prop was fowled. Overloading will make it smoke too! Glad you got it fixed!