Chainsaw question for you experts

sms · Mar 9, 2014

Saw in question Husqvarna 372. Second time this
happened. Cutting trees yesterday just after
lunch, filled saw for third time bucked butt end
and limbed about half way up tree (24" butt
hemlock) saw started running lean and quit
wouldn't restart. Tried it this afternoon and
started as normal. First time this happened I
pulled fuel filter cleaned it seemed fine blew
things out didn't take carb off, cleaned and
checked plug, thought saw was ok. I would like to
work more then half a day with saw any ideas where
to start out there? I was also skidding trees out
so saw cooled some between trees. Thanks in
advance. sms

old · Mar 9, 2014

Blowing the filter out is a half sort of get you by fix. Those filters are made to be replaced when they clog up not be blown out so time to break down and replace the throw away fuel filter or air filter or both

37chief · Mar 9, 2014

These small motors have a even smaller carb. They have diaphragms that get stiff from continued heat. I have found just by installing a carb kit the two cycle motor will work. I have only experienced one electronic failure in a lot of years of two cycle motors. Stan

D beatty · Mar 9, 2014

If I'm not mistaken there is a small filter in carb that can plug. I had similar problem with Husky 50 Special and it ran fine after both fuel filters were replaced.

TomH in PA · Mar 9, 2014

Check the fuel line, it might have a small crack that"s leaking air.

T.R.K. · Mar 9, 2014

These are just some thoughts:

I am betting its your fuel. Are you running regular gas? How old is your fuel? How old was the oil you put in the mix?

1. Pour the gas in the tank into a clear container (I use an old plastic peanut butter jar at work. The large mouth makes it easy to catch most of the fuel from the saw"s tank.) See if any water settles out of it. If you do, it is the ethanol in the fuel. That is called "phase separation" It is very bad for the saw as the oil won"t mix with the alcohol in the water. So not only is she lean, she"s running dry with no lubrication, too.

2. Check the little screen in the carburetor where the fuel goes in. It may be clogged.

3. Replace the fuel filter.

4. The fourth thought is the little hose between the carburetor and the cylinder is not sealing and that is causing a lean run because the carburetor is not getting enough pulse from the engine to work the diaphragms. I do not know if the 372 has this hose or not though.

5. Your saw has an air leak that only manifests itself when it is hot. Probably at one of the crankshaft seals.

notjustair · Mar 9, 2014

My Sachs was doing that a month ago. I was trying to use up the old fuel. New batch of fuel with Stihl oil and it has run like a striped ape since.

Paul for Wi · Mar 9, 2014

Have the same saw, and had a problem with it running lean also. After doing alot of things I finally checked the carb. and there was a small piece of plastic or gasket against the main jet.

onefarmer · Mar 9, 2014

Could be split line-fuel and crank-pressure, diaphragms, plugged carb-there is a screen in there, and/or crank seals.

Bret4207 · Mar 10, 2014

Bad filter, bad fuel line, bad diaphragm, generally gunked up carb, bad seals, bad gasket, loose head, bad carb block or intake boot, bad fuel, bad needle or seat, worn needle stirrup or shaft, leaking carb, worn carb shaft.....it's your choice. Start at square one and tighten things up, then go methodically from there.

8v92guy · Mar 10, 2014

If is a newer x torqe those new carbs kinda suck. have you checked tank vent?

Bill(Wis) · Mar 10, 2014

Possibly a cracked fuel line (inside the tank). Age, ethanol, etc. can cause that. Will suck fuel when submerged but as soon as it can suck air, it will. Also, as mentioned below, check for blocked filler cap vent.

Brian Dan · Mar 10, 2014

I have a Husqvarna 272xp that did the same thing.
The Ignition mogul when hot would not fire.
Replaced mogul and saw ran fine.
Brian

pat sublett · Mar 10, 2014

Most common problem in order 1.bad fuel line 2. clogged spark suppressor screen on muffler. 3.vacium leek in rubber boot between carb and cylinder. number 3 is very rare but will drive you crazy.

Chainsaw question for you experts

sms

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old

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37chief

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D beatty

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TomH in PA

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T.R.K.

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notjustair

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Paul for Wi

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onefarmer

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Bret4207

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8v92guy

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Bill(Wis)

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Brian Dan

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pat sublett

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