Husqvarna 570 wont run

[Roscoe294]

I have a 570 that is a couple years old and probably has about 40 tanks of gas through it. It ran perfect until one day it started to bog when under power. Then it got real bad to the point where it would only idle and die out under any throttle whatsoever.

I know nothing about small engines so I had a buddy look at it that is familiar with them and uses Husqvarnas at a tree service.

The carbs been gone through, cleaned / adjusted........same problem.
Thought it had an air leak at the base gasket, cleaned / replaced............after he said he ran two tanks through it w/o a problem. I get it, run it 10 minutes and guess what..........same problem.

I gave it back to him and he cant figure it out. He said they have the same problem with 359's they use for tree service.

Any help is appreciated

 

[pioneerguy600]

The 359`s have defective Walbro carbs and intake manifold clamps that allow air leaks.
Pioneerguy600

 

[Roscoe294]

thanks for the info Pioneerguy600

Tech Data on the 570 shows a ZAMA carburetor, which mine has.

Anyone else????????

 

[taplinhill]

I'd pull the muffler and make sure the piston looks good. Then make sure your muffler screen is clean. Have you looked at the spark plug?

 

[hamish]

Do a compression test and tell us the readings, then do a vaccum and pressure test on the powerhead (testing your seals and gaskets and fuel tank (testing your lines and tank vent), then let us know what you get.
And we will help you from there.

 

[Roscoe294]

I'd pull the muffler and make sure the piston looks good. Then make sure your muffler screen is clean. Have you looked at the spark plug?

Muffler, piston, spark plug are all good to go.

 

[Roscoe294]

Do a compression test and tell us the readings, then do a vaccum and pressure test on the powerhead (testing your seals and gaskets and fuel tank (testing your lines and tank vent), then let us know what you get.
And we will help you from there.

Compression test can be done. Pressure test, not sure I have the tool(s).
thanks

 

[hamish]

Whats your compression at?

 

[Roscoe294]

Ok, I think I traced the problem to a little plastic tube/line possibly called an "impulse line"? It was cracked originally, replaced, then just overlooked by my buddy the second time it started running like crap. Found it was cracked again, replaced it, only this time with a bit more slack in it. So I will see what happens.
Thanks for every ones help

 

[chainsawworld]

I am looking at a 570 that a guy wants to sell. Of coarse it is not running. Compression was at 90psi. Yanked the muffler off to find the piston is scratched to to heck. Dug deeper by pulling the jug off and found the piston is shot as well as the ring. Jug may be possibly cleaned up with a ball hone. I am really concerened with the crank seals and the intake manifold. The intake manifold is nuts. Looks like lots of possiblities to develope a leak. Any thing in the 500 series scares me as far as leaks in the crank seals.
Some say this is a strong saw while others are afraid of the seals. Definitly not a 372xp.
Can not wait to see whats next with this saw. Marty

 

[Roscoe294]

Update a year later: The little rubber hose was the problem. The saw rips like the day it was new.