Ignoramus27122 wrote:
On Thu, 01 Sep 2005 04:42:16 GMT, Howard Eisenhauer wrote:

I'm looking at buying an Onan genset. It's a late 80's vintage 4 cyl
aircooled diesel unit, 120/240 single phase. Seems to be the same
model unit shown here-


Is it Onan DJC? If so, I have an Onan DJE, a very similar unit, only 2
cylinders instead of 4.

http://igor.chudov.com/tmp/onan/Diesel/


http://cgi.ebay.com/ws/eBayISAPI.dll...ayphotohosting

As far as I can tell it has about 1500 hours on it since it's last
rebuild. I had the seller fire it up today & after warming up it was
blowing white smoke . The owner sez it was fine last time he ran it
back in June. It also seemed to take a while to settle down before it
ran evenly although there may have been some air in the fuel line.

Q.- Any ideas what the white smoke is all about? Is this likely to be
a tuneup item or something more serious?


white smoke is unburned, atomized diesel fuel.


Q.-What's a rebuild on one of these things cost?


A lot, but... Why would you need a rebuild? They will outlast you.
To get rid of the white smoke.

Q.- Anything in particular I should be looking for/concerned about
with one of these units?


If it starts, and runs, it is in a good shape.
Except that it is obviously running on 3 cylinders (or less).
If you can crank it over by hand (with the injection pump set to
shutoff), you can see if there is an obvious lack of compression
on one cylinder. (I think it is pretty clear, even from this
distance, there will be.) You might be able to determine which
valve (if any) is the cause. If intake, it might just be a sticky
valve, and an oil change and a warmup to full temperature might
clear it up. If exhaust, that could be a burned valve, which will
take a little more work and money to fix. Some Diesels have emergency
shutdown mechanisms that lock the exhaust valves open in case the
governor or fuel pump malfuctions. If this engine is so equipped, it
could be that the emerg. shutdown mechanism has gotten out of adjustment
and is holding one valve open. Most of these schemes have a system of
levers that come through the valve cover, so it should be quite obvious.

Jon