I mentioned this a few weeks back....mid June my Yanmar 2 GMF was
producing black smoke when starting up and would not rev above 2,100 RPM's.
Late last season, I decided to do some regular maintenance and checked
my air filter....there was no air filter material...it had
disintegrated....didn't have a new one on hand so genius here cut a
piece of sponge and fitted it in the metal ring. Engine worked fine.
But over the winter the sponge more than likely absorbed some water
which would restrict air flow through it.
I had a new Yanmar air filter on the boat which I got late last year and
never installed....changed out the sponge and replaced with new one, and
guess what, in neutral, the engine revived up to 3,400 ....ran the
engine in forward gear at the slip for another 20 minutes.... shut the
engine off...started again...revved up and down....engine works as it
should.
The problem was a lack of air....explains where the smoke was coming
from and the low RPM's....incomplete combustion because of restricted
air flow.
Rob Abbott
AZURA
C&C 32 -#277
Halifax, N.S.
On 2022-07-19 8:20 a.m., Joe Della Barba via CnC-List wrote:
If the exhaust hose is on fire, it sure can!
Normally it indicates a very rich mixture, which in a diesel means the
engine is constrained in some way like being over-propped or with a
clogged air filter.
Joe Della Barba
Coquina C&C 35 MK I
Kent Island MD USA
*From:* Robert Abbott via CnC-List <[email protected]>
*Sent:* Monday, July 18, 2022 6:13 PM
*To:* Stus-List <[email protected]>
*Cc:* Robert Abbott <[email protected]>
*Subject:* Stus-List Re: Sea Foam
Also, lots of black smoke can be either a fuel problem or a lack of
air problem
On 2022-07-18 1:44 p.m., Matthew via CnC-List wrote:
Lots of black can be overheating.
