This is an old thread. Now an update after 500 hours of use.
The smoky Yanmar
has performed well over 500 hours and almost three years. I have had a couple of problems -- oil puking into the bilge
after operating in rough, high seas a couple of times. Gummed up turbo after those incidents; cleared up by itself once.
I replaced all of the fuel
injectors last summer -- that was the last bit not to have been overhauled (at delivery
, the turbo and injection pump were overhauled in an unsuccessful attempt to address the smoking problem).
I would sometimes get a fair amount of grayish smoke with a blue tinge on startup, sometimes smoky exhaust
, but I learned to ignore it, and the engine has been performing well. I had not seen the really huge billows of smoke I had when I was buying
Now a funny
thing happened -- I have been using the main engine to charge batteries since my generator
broke. So I have been running it at 1300 - 1500 rpm
for an hour or two at a time, once a day.
Today I decided to blow the cobwebs out a little, put her in gear
, and ran her up to 3000 rpm
. Huge billows of smoke, like when I was buying
her! After a few minutes of running in gear
at 3000 rpm, the smoke disappeared.
This makes me think that the smoke comes from accumulation of unburned fuel. Maybe the injection is adjusted incorrectly, so that too much fuel is injected at low load conditions. This is bad, isn't it? Called "wet stacking", or something? Can wash oil off the cylinder bores and ruin them?
Or what do you guys think?