My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just to
see if it would go the recommended redline. But now it will only go
2800 rpm full squeeze. And at 2800 rpm (either at the slip or under way)
it puts out a little whitish smoke. I've been thru the fuel system and
so far can't find anything that would be limiting the fuel flow (new
hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?

Thanks

On Sat, 30 Oct 2004 01:22:48 GMT, "1.156" wrote:

Any suggestions of other reasons this thing won't go full blast.?

================================

Dirty bottom, dirty or bent prop?

While reading rec.boats.cruising, I noticed "1.156"
felt compelled to write:

My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just to
see if it would go the recommended redline. But now it will only go
2800 rpm full squeeze. And at 2800 rpm (either at the slip or under way)
it puts out a little whitish smoke. I've been thru the fuel system and
so far can't find anything that would be limiting the fuel flow (new
hoses, new filter elements, etc).

I had one of these, and from memory white smoke meant:
1./ Retarded injection timing
2./ Insufficient compression.
Either of those would knock 600 RPM off the top.

I seem to remember that they were meant to develop 13hp @ 3400, but
rev out to 3700-odd redline, although I never got mine over 3500.

Might be a stuffed injector, or a badly adjusted valve. At the more
expensive end of town, a head gasket or broken ring or worse.

One thing I found with this engine (I'm assuming you have raw water
only cooling) were similar symptoms if the raw water system was
getting too clagged up and the temp was elevated, although not so much
white smoke, admittedly.. Might pay to check that, too.

Any suggestions of other reasons this thing won't go full blast.?

Those are the best I can do, but I'm no expert

Ian

While reading rec.boats.cruising, I noticed Wayne.B
felt compelled to write:

On Sat, 30 Oct 2004 01:22:48 GMT, "1.156" wrote:

Any suggestions of other reasons this thing won't go full blast.?

================================

Dirty bottom, dirty or bent prop?

At the dock? :-)

"1.156" wrote
My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just to
see if it would go the recommended redline. But now it will only go
2800 rpm full squeeze. And at 2800 rpm (either at the slip or under way)
it puts out a little whitish smoke. I've been thru the fuel system and
so far can't find anything that would be limiting the fuel flow (new
hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?


Are you sure about the rpm? Some aftermarket tachometers have to be set up
for the number of teeth on the flywheel and can lose this setting. If it is
the factory tach, you should be ok.

Other things could be:
- fuel starvation (Racor or engine filter plugged)
- high pressure pump needs rebuilding/replacing.
- Exhaust elbow plugged - Take it off and inspect exhaust and water sides.
- Throttle cable stop incorrectly set
- Governor incorrectly set.

I am not sure, but I believe that the engine will not run at full rpm with
no load - something to do with the governor.

If you can't find the problem yourself (you should have manual to understand
how it all works), check with an experienced Yanmar mechanic who has seen
this type of problem before - otherwise you may change everything before you
find the cause!

There are also other internet forums that discuss Yanmars - I think that
Torreson have one http://www.marinedieseldirect.com/power/forums.php and
then there is http://www.yanmarhelp.com/

Good Luck

At the dock the engine should rev right up in neutral. If it won't do that, there may
be a problem in the governor, or injectors or injector pump.

In gear at the dock, it will probably blow black smoke long before it gets to 3000
rpm.

BTW, you didn't mention how many hours the engine has. If the injectors are over 1000
hours its probably time to have them checked.

"Ian George" wrote in message
news
While reading rec.boats.cruising, I noticed Wayne.B
felt compelled to write:

On Sat, 30 Oct 2004 01:22:48 GMT, "1.156" wrote:

Any suggestions of other reasons this thing won't go full blast.?

================================

Dirty bottom, dirty or bent prop?

At the dock? :-)

"1.156" wrote in message
...
I've been thru the fuel system and so far can't find anything that would
be limiting the fuel flow (new hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?


Pull the injectors, take them down to a shop that specializes in diesel fuel
systems and have them tested. If they are worn then they don't create the
proper spray to atomize the fuel and the performance degrades significantly.
The injectors can often be rebuilt (replacing just the tips) or you may need
to replace the entire injector.

Rod

carbon buildup in exhaust ?


"1.156" wrote in message ...
My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just to
see if it would go the recommended redline. But now it will only go
2800 rpm full squeeze. And at 2800 rpm (either at the slip or under way)
it puts out a little whitish smoke. I've been thru the fuel system and
so far can't find anything that would be limiting the fuel flow (new
hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?

Thanks

Lots of suggestions, thanks. I think I've ruled out all but serious
problems with the engine like injectors or bad compression. Doesn't
look like an easy fix.

Thanks and regards to all to took time to help.

1.156 wrote:

My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just
to see if it would go the recommended redline. But now it will only
go 2800 rpm full squeeze. And at 2800 rpm (either at the slip or under
way) it puts out a little whitish smoke. I've been thru the fuel
system and so far can't find anything that would be limiting the fuel
flow (new hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?

Thanks

Scince I once had that problem, I go for the carbon build up in the exhaust
elbow.

"Roy G. Biv" wrote in message
om...
carbon buildup in exhaust ?


"1.156" wrote in message
...
My Yanmar 2gm used to go 3400 rpm -- I did it a couple of times just to
see if it would go the recommended redline. But now it will only go
2800 rpm full squeeze. And at 2800 rpm (either at the slip or under way)
it puts out a little whitish smoke. I've been thru the fuel system and
so far can't find anything that would be limiting the fuel flow (new
hoses, new filter elements, etc).

Any suggestions of other reasons this thing won't go full blast.?

Thanks