Sounds to me like it's trying to turn way too much screw at way too
much pitch. How fast will it run in neutral with no load? Does it
smoke like hell with no load?

Overloaded diesels, especially simple, naturally-aspirated diesels,
smoke like hell, ugly clouds of black smoke caused by unnatural
burning in a cylinder that's pressing too hard back on the fire above
it, producing lamp black (carbon).....soot! As it will run out of
oxygen on each burn because the load is choking the hell out of it and
it can't breathe, unburned fuel oil is also unceremoniously dumped out
the stack into the waterbox....and waterway.

Just my silly opinion from years of diesel ownership...(c;
It's only 18 HP, right?


On 8 Mar 2004 15:37:41 -0800, (Sebastian)
wrote:

Our 1986 Catalina 27 with Universal 18 diesel tends to run hot
(although not immediately, takes many hours), has low RPMs (always,
although it ranges between 1750 and 2000 at full throttle), and always
give off some black smoke. Additionally, it appears that there may be
a tiny bit of black oil leaking behind the transon of the boat, but
not a lot. Finally, we get a maximum speed of 4 1/2 or 5 knots in
still water, which seems to be too little...

I am quite new to diesels, so know very little. Can someone recommend
some easy things to check/fix. I've heard black smoke means injectors,
but could that also cause the low RPMs?

Thanks!


Larry W4CSC
POWER is our friend!