Easy fix? Saw won't rev

[Spruce_Goose]

Hi.

So I am hoping some people might weigh in on some chainsaw troubleshooting. I'm using Husqvarnas. I know that it is difficult to describe a problem and know how to identify, but it is a common problem and maybe one that can easily be traced (I hope).

The saw will start fine, but when you give it throttle it'll groan at you without reaching proper chain speed. Kind of like the sound it'll make if revved with the brake on, but a little more low and sputtery. It is a very common thing when a saw is first started, and can oftentimes be overcome by goosing the throttle a couple times, but some saws will continue to do it indefinitely. I believe this to be lack of fuel, but why I am not sure? Is it a carb thing or a fuel filter thing, or some other thing entirely (or, most likely, can it not really be pin pointed on that info alone?)

In the likely case it cannot be pin pointed, how would one go about narrowing down and fixing the problem? (I am not a mechanic, but am pretty handy and have a basic understanding of engines, and the making of chainsaws. I have not rebuild engines but have tinkered with many other things on the saw besides the actual piston/cylinder itself.)
Any links to resources would even be appreciated.
Thanks,
TYler

[beenthere]

Fresh gas mix?

Replaced plug?

Adjusted carb?

[MidWestTree]

What model are you working on? You could have an air leak, impulse problem, lots of possibilities. Did it just act up suddenly or has it been getting progressively worse?

[celliott]

Possible the spark arrestor screen in the muffler is plugged up with carbon?
Just a guess.

[pineywoods]

Mudd daubers in the muffler...

[joe_indi]

It might be the result of the flywheel twisting slightly from a damaged key. This retards the timing.Its happened to me on a couple of Huskys 365, 372 and 385. (especially the 385)

Joe

[TimRB]

Possible the spark arrestor screen in the muffler is plugged up with carbon?

Exactly that happened to me recently.  One thing to check is the sparkplug; if it's black from running rich, pull the screen and burn it clean with a propane torch. 

I found this out the hard way--couldn't figure out what was going on with the saw, so surrendered it to the repair shop. 

Tim

[Al_Smith]

Exactly that happened to me recently.  One thing to check is the sparkplug; if it's black from running rich, pull the screen and burn it clean with a propane torch. 

Tim

Pull the screen out and throw it away if it plugs that bad .

[clww]

[/quote] Pull the screen out and throw it away if it plugs that bad .
[/quote]
+1

[Spruce_Goose]

its husqy 346xp and 357xp (its a fleet of saws for trail crew, and a few of them are doing it). They sat over winter, possibly with half tanks of gas... Perhaps a problem?

[Al_Smith]

Well if that's the case dump the old fuel ,regas it and open up the high speed jet a tad until it clears itself then lean it back down to where it's running good .Carbs get squirrely with old gas in them .

[MidWestTree]

its husqy 346xp and 357xp (its a fleet of saws for trail crew, and a few of them are doing it). They sat over winter, possibly with half tanks of gas... Perhaps a problem?

The Husky 357 and 359's had an issue and service bulletin with the old style plastic clamp on the partition and intake boot. If your saw does not have a metal clamp on the boot between the carb and cylinder that's likely your problem, they leak air and don't feed impulse to the carb sometimes causing your symptoms. Check the piston for scoring as well, air leaks at that plastic clamp will do serious damage in a hurry.

[1270d]

Don't tinker with jetting unless you have a clean fuel and air filter.