Husky 350 problems

[Nichmo]

I bought a husky 350 12 years ago and its been a great little saw. Back in August while bucking some logs I noticed the muffler had come loose so I tightened that up and keep an eye on it thereafter. A week later I noticed it didn't sound right...checked muffler and it was tight. Started cutting again and had no power in the cut, set it down and the rpms picked up...if I pressed on the handle the rpms would pick up....pick the saw up and would return to normal. Quit for the day took it home to check it out. I noticed the bellows were loose at the cylinder because the plastic clamp was broke. Took carb off and took muffler off and I noticed the piston and ring were badly scoured.
I ordered a new meteor cylinder and piston, crank bearings and all new parts from cylinder to carb. Saws been running great till yesterday with maybe 5 tanks of gas through it. Just for the heck of it I took the muffler off and low and behold scuff marks on the piston. Not enough to feel with fingernail but there. I've been running 40:1 mix with the screws on the rich side. Checked compression and I get 145 psi. Is light scuffing normal...it's a single light mark right in the middle of the exhaust port. Should I just run it or tear it down again. I have no way to vacuum or pressure test.

 

[Ozhoo]

Welcome to AS. Post up a picture so we can see what you have going on.

 

[Huskitoter]

Welcome to AS.

It's always good to get info like this on AM parts.

 

[grizz55chev]

Look up pressure vac test, then read, read, read.

 

[NSEric]

Since it has good compression I'd just run it.
Minor scuff marks don't hurt anything, if they were deep enough to effect ring sealing the compression would be lower.

 

[holeycow]

Could have been a piece of debris from the rebuild..?

Gotta be clean, clean, clean

 

[grizz55chev]

They are known vacuum leakers, scorched cylinders are common in this model. Keep running it lean and you’ll be back to squar 1 in a heartbeat. Vacuum check is critical, I can’t stress this enough.

 

[Nichmo]

They are known vacuum leakers, scorched cylinders are common in this model. Keep running it lean and you’ll be back to squar 1 in a heartbeat. Vacuum check is critical, I can’t stress this enough.

I can pull it apart again to vacuum test, but I still have no way to pressure test, my mighty vac only does vacumm. I do have a leak down tester from when I used to work on auto engines if I can adapt that to very low pressure.
Where does the piston need to be when doing these tests...TDC or BDC.

 

[Nichmo]

Could have been a piece of debris from the rebuild..?

Gotta be clean, clean, clean

I guess thats possible, although I tried to make sure everything was spotless something could have gotten in as I was lowering the cylinder over the piston.

 

[cuinrearview]

Was the new intake clamp metal or plastic? I'm sorry if you stated it already and I missed it.

 

[Nichmo]

Was the new intake clamp metal or plastic? I'm sorry if you stated it already and I missed it.

The new intake clamp is metal.

 

[Mattyo]

What did you reseal the bearing cap with?

Check the head bolts for loosening

 

[Nichmo]

What did you reseal the bearing cap with?

Check the head bolts for loosening

The crankcase base was sealed with Dirko and I put just a smear of Dirko on the cylinder gasket. I checked the cylinder bolts after the first tank of gas. When I got home I ran it to get it warm and then I removed the handle/gas tank and checked the bearing cap/base for tightness and it was fine.

 

[Nichmo]

I thought this was strange and not what I remember from working on cars.....The compression was 145psi on a cold saw, after starting it and getting it good and warm the compression dropped to 125psi.

 

[cuinrearview]

I thought this was strange and not what I remember from working on cars.....The compression was 145psi on a cold saw, after starting it and getting it good and warm the compression dropped to 125psi.

That's normal. All of your tolerances expand with heat.

 

[old guy]

Yup, I always get lower reading on a warm or hot saw.

 

[Nichmo]

Yup, I always get lower reading on a warm or hot saw.

Just the opposite of what I used to get working on auto engines.....was always higher on hot engine and was always reccomended to perform test on hot engine.....my first time working on 2 strokes.

 

[Nichmo]

I'm going to buy a mightyvac pressure/vac tester and test it next week....if no leaks I'll spring for a new carb and run the heck put of it. In the meantime I'll use my stihl 291 to finish bucking the logs I have for next years firewood.

 

[RAM2940]

I had the same issue with a 357xp. I bought a running saw but had trashed cylinder and piston for $50. Purchased new meator cylinder and piston, carb, intake bellow and clamp, basically everything new. rebuilt had problems getting it to start. Purchased another carb and now runs good, but i noticed the same scuff mark dead center on exhaust side of piston, feels smooth, but scuffed, happened very soon after i got saw running.

 

[wilsonishere]

Betting you have a vacuum leak, I had a 350 that the rubber boot that connects the carb to the cylinder (intake tube) aged on and got some small cracks. The cracks did not look bad but I cleaned it up and did a silicone job. Low and behold it ran fine. So i ordered a new intake tube. I also have seen crank seals do the same thing. If you turn the saw on its side and the idle changes either way I would say look to the crank seals. The 350 is a great little saw!