Husqvarna 353 - at a loss here, need help

[singinwoodwackr]

Check to see if the last carb rebuild got the right kit. I recently went through that

 

[huskihl]

Check to see if the flywheel key is sheared and check the spark arrestor screen to see if it’s plugged up

 

[a. palmer jr.]

I get so many saws that don't have a history that I usually just have a routine that I go through, compression, spark, pressure/vacuum test. On the last saw I just bought a kit online which consisted of ignition module, carburetor, fuel and oil hoses and filters, etc. These kits are about the same price as a carburetor would be..

 

[hunter72]

I got one from a member about 4 to 5 years ago and he said it would spit sputter and when it run it would rev very High put would not pull a load . It did everything he said but would die when first sign of a load. It was the electronic ignition. Saw is with a friend up north in Wi.for the last few years cutting firewood.

 

[quattro.pilot]

If it were me I'd be considering that I was now at the point of individually swapping in known good substitute parts for testing....probably starting with the carb.

All of the rebuilding you've previously described should have been enough to fix/solve any major problems. So unfortunately you're now in process-of-elimination mode.

I don't know what your experience is with 3-series, but that 544 45 29-01/503 86 64-01 part is all plastic, you carve the coarse-thread bolts into plastic, and overtime they don't hold for sh*t you can't tighten them enough without risking stripping. On a saw rebuild I'm almost always just replace the 503 86 64-01 for good measure. Such a cheap design and Husqvarna should be ashamed...especially when the 372 equivalent "carriage" has capture metal nuts instead.

My money is on a fuel-related gremlin.... you did put the piston in the correct orientation, right?

 

[MartDalb]

I will follow up later tonite with all this lovely input. Thanks everyone.

As regards to the piston, I have not had the piston off. It was a cheap deal non running saw, I knew what I was getting.
Did not predict it to be this hard to diagnose though.

(Double checked, piston had the arrow correctly pointing towards exhaust)

 

[MartDalb]

If it were me I'd be considering that I was now at the point of individually swapping in known good substitute parts for testing....probably starting with the carb.

All of the rebuilding you've previously described should have been enough to fix/solve any major problems. So unfortunately you're now in process-of-elimination mode.

I don't know what your experience is with 3-series, but that 544 45 29-01/503 86 64-01 part is all plastic, you carve the coarse-thread bolts into plastic, and overtime they don't hold for sh*t you can't tighten them enough without risking stripping. On a saw rebuild I'm almost always just replace the 503 86 64-01 for good measure. Such a cheap design and Husqvarna should be ashamed...especially when the 372 equivalent "carriage" has capture metal nuts instead.

My money is on a fuel-related gremlin.... you did put the piston in the correct orientation, right?

Yeah, thought did cross my mind if the carburator was acting up weirdly.

I can get an AM carb + Coil for very little, combined with a new manifold and clamp part, It won't be too bad an expense.
I don't have any swap in items for Husqvarna saws, sadly.

I will be going through the parts again, checking piston, oil seals, flywheel.
Coil looked fine, and I did take the carburator apart twice to recheck, using my own carb kit etc.
So unless it's oddly defective in a way I haven't seen, ever. I guess it is best to start with the parts I know are broken, manifold + clamp part.


I truly appriciate all the feedback here, I am sure I will find the issue.......but it might be a while

 

[MartDalb]

Timing might be out, probably worth checking coil, gap, flywheel etc

Does this actually happen to saws that ship out, gets used and then suddenly doesn't work correctly?

I ask because, I have had many saws on my table, trimmers etc. as well. Never seen a "bad timing" machine.
I am interested in it though, never had to try and test, no idea how either.

 

[rupedoggy]

Thing is that saws are generally started by yanking the flywheel around. The nut is supposed to hold the thing tight enough so it does not turn on the taper. The key is aluminum on some saws and easy to break. Sometimes the saw kicks back or otherwise makes funny jerky movements. The flywheel is not quite where it is perfectly timed but close enough to run (badly). Think about it.
I generally test by holding a dowel in the cylinder plug hole, and gently bringing the piston to TDC. The magnets should be just at or slightly past the coil. The spark has to arrive just before it hits TDC.

 

[MartDalb]

Thing is that saws are generally started by yanking the flywheel around. The nut is supposed to hold the thing tight enough so it does not turn on the taper. The key is aluminum on some saws and easy to break. Sometimes the saw kicks back or otherwise makes funny jerky movements. The flywheel is not quite where it is perfectly timed but close enough to run (badly). Think about it.
I generally test by holding a dowel in the cylinder plug hole, and gently bringing the piston to TDC. The magnets should be just at or slightly past the coil. The spark has to arrive just before it hits TDC.

I will pop off the flywheel and check it, and go through what you wrote here, thanks!

 

[MartDalb]

Thing is that saws are generally started by yanking the flywheel around. The nut is supposed to hold the thing tight enough so it does not turn on the taper. The key is aluminum on some saws and easy to break. Sometimes the saw kicks back or otherwise makes funny jerky movements. The flywheel is not quite where it is perfectly timed but close enough to run (badly). Think about it.
I generally test by holding a dowel in the cylinder plug hole, and gently bringing the piston to TDC. The magnets should be just at or slightly past the coil. The spark has to arrive just before it hits TDC.

Help me out here

Having the cylinder off, I can feel when the piston starts going downwards again.
See pictures, this is TDC, best I can do with this (probably crude) method.
Anything out of the ordinary here?
(edit, disregard the coil/flywhel distance, I had the coil off and just poped it in to check TDC)

 

[Wood Doctor]

The gap is supposed to be about 0.01", or about the same as the thickness of a business card. Yours looks OK in the second Pic. I doubt this is the problem. Not sure we should have disregarded that, especially since you took the coil off.

 

[MartDalb]

The gap is supposed to be about 0.01", or about the same as the thickness of a business card. Yours looks OK in the second Pic. I doubt this is the problem. Not sure we should have disregarded that, especially since you took the coil off.

Yeah, as I wrote, the coil was just slapped into place with no regards to gab. I will sort the gab out later.

It was just to test that tdc.

The gab, before I took it out, was pretty solid, I checked with a business card before taking it out.

 

[J D]

Given that you don't know the history of the saw it's possible someone tried advancing the timing, had set the gap wrong (depending on what it was before) or has been using the wrong plug for long enough to damage the coil.
This:

Is where the 345 at hand in bits sits at top dead center

 

[rob066]

quality of gas? We know how ethanol likes to suck water.

 

[Cantdog]

quality of gas? We know how ethanol likes to suck water.

The OP is in Denmark so I doubt he has our ethanol issues.

I am still interested in the melted intake...........OP.......do you think the melting came from engine heat or chemical reaction to fuel or additives in the fuel?? I'm having a hard time seeing a saw get so hot as to melt the intake boot and manifold without toasting the piston.........your piston looks mint.....used mint...but mint.....

 

[huskihl]

The OP is in Denmark so I doubt he has our ethanol issues.

I am still interested in the melted intake...........OP.......do you think the melting came from engine heat or chemical reaction to fuel or additives in the fuel?? I'm having a hard time seeing a saw get so hot as to melt the intake boot and manifold without toasting the piston.........your piston looks mint.....used mint...but mint.....

It could be an aftermarket boot. The original Chinese 372s came with a standard hose clamp and I’ve seen the plastic oozed right out through the worm drive slots. More plastic than rubber

 

[Hdtoolmkr765]

Have you checked compression with a gage?

 

[grizz55chev]

It could be an aftermarket boot. The original Chinese 372s came with a standard hose clamp and I’ve seen the plastic oozed right out through the worm drive slots. More plastic than rubber

+1! Seen it on a couple of occasions, never buy Chinese carb boots, EVER!

 

[KASH]

Years ago I bought several saws with timing issues the seller would say the saw was not running right so I put in new points.The saws would almost start and I knew right away the flywheel was toast because they did not index the flywheel groove to the keyway.I would buy the saw cheap and source a used flywheel now that I know better I would have set the flywheel in the correct position and too hell with the key.
Kash