G
Guest
Guest
we seem to have a black smoke/carbon trail having cleaned the injector. Any ideas, we do not have a workshop manual
John & Tony Wardale
John & Tony Wardale
philip_stevens
Active member
From what you are saying, it looks as though your injector is injecting too much fuel. Possibly a new injector is required, or get the one you have looked at again, as it could have a foreign object under the seat and it unable to properly close, or opening too far.
The unlikely alternative is that there is an air restriction.
Having a Bukh DV20 myself, I would think injector.
Taken from my workshop manual, the opening pressure must lie on 150+/- 10 kg/cm2.
regards,
Philip
The unlikely alternative is that there is an air restriction.
Having a Bukh DV20 myself, I would think injector.
Taken from my workshop manual, the opening pressure must lie on 150+/- 10 kg/cm2.
regards,
Philip
G
Guest
Guest
Thank you for the suggestion. We have just had the injector serviced but will ask them what settings were used.
I wonder if the fuel pump is the trouble. The exhaust is fine on low to medium power. the black smoke pours out when on a good load.
the compression also seems fine as the engine fires after 2-3 revs
kind regards
Tony Wardale
I wonder if the fuel pump is the trouble. The exhaust is fine on low to medium power. the black smoke pours out when on a good load.
the compression also seems fine as the engine fires after 2-3 revs
kind regards
Tony Wardale
philip_stevens
Active member
I've just remembered. Max revs, and therefore pre-black smoke, is adjusted by screwing the stop solenoid in and out.
The engineer who adjusted my DV20 took the boat for a run and adjusted the solenoid to just under black smoke, and also to max revs. I had changed the prop from a two bladed to a four bladed, and the adjustment was made to accommodate the 4 blade prop.
If I still go from tickover to full revs straight-off, I do get black smoke for a few secs until the boat is underway, and the load off the prop.
From this latest thought, you may be over-revving the engine. Something else to look at.
regards,
Philip
The engineer who adjusted my DV20 took the boat for a run and adjusted the solenoid to just under black smoke, and also to max revs. I had changed the prop from a two bladed to a four bladed, and the adjustment was made to accommodate the 4 blade prop.
If I still go from tickover to full revs straight-off, I do get black smoke for a few secs until the boat is underway, and the load off the prop.
From this latest thought, you may be over-revving the engine. Something else to look at.
regards,
Philip
philip_stevens
Active member
Errata. For 4 blade prop, read 3 blade prop. I have a sailing boat, not a power boat. My error - the prop, not the sailing boat!
regards,
Philip
regards,
Philip
G
Guest
Guest
Thank you for the solenoid tip. We went out yesterday evening with a marine mechanic and adjusted the solenoid until we got rid of the black exhaust.
The baot is slightly overpropped so we will reduce the pitch in the winter
kind regards
Tony Wardale
The baot is slightly overpropped so we will reduce the pitch in the winter
kind regards
Tony Wardale
philip_stevens
Active member
Thanks for coming back to let us know. It is good to know when things work out right.
Good sailing for the rest of the season.
regards,
Philip
Good sailing for the rest of the season.
regards,
Philip
