372 leaning itself out while milling.

[IndyIan]

I've finally got down to some serious milling this weekend and half
way through my first beam my saw suddenly went lean on me. Revved up
like I was running out of gas, except I didn't run out of gas... The
saw wouldn't 4 stroke at all when free revving it. Anyone
have any idea what's going on?

I learned how to adjust the highspeed screw limiter and set the
carb so it would 4 stroke unloaded like it should and kept on milling
for the rest of the day with out problems.

This is the second time this has happened to me while milling, first
time I took it to my dealer and they set the carb with the tach. I
used the saw for a few hours regular cutting and some milling before
the saw went lean on me again this weekend.

It almost seems like the highspeed screw vibrates and changes the
adjustment but with the limiter on it I can't see how that would
happen.

Any info would be appreciated!
Ian

[Kevin]

Check the position of the fuel line in the tank, maybe it's sticking up in the tank where the fuel isn't when the saw is on its side.

[IndyIan]

Ah, good idea Kevin, I'll have a look at that.  The saw does seem to stay lean though even when it's right side up.

[ladylake]

I'd check out the fuel tank vent. Or loose carb or air leak

[Tom]

Welcome, Ladylake.

[IndyIan]

Thanks for the input everyone.  I'll take a close look for air leaks in the intake tonight.

Is spraying starter fluid on the outside of the intake a good way to find leaks?  Any downsides to doing this?

[ladylake]

 :)Indylan.
Did you get it figured out yet? I'd sure be leaning towards your vent line getting clogged. Lots of dust milling.

[IndyIan]

Ladylake,
I have to admit I haven't got around to looking at it yet...
Thanks for asking though!  I'll post what the problem is when I find out.
Ian

[IndyIan]

Well, I took the saw to the dealer and they went over it again and found that the fuel pump diaphram had dried out.  Makes it leak I assume.  I'm picking the saw up tonight and will be cutting/milling this weekend.
Hopefully everything is good for a long time now.  It's hard to spend that much money on a saw and have problems with it.