Scored 562

[Deets066]

I scored a 562 the other day..... Which also happens to have a scored piston.

What are some of the notorious causes for scoring with these auto tunes? My guess is straight gassed but I want to cover my bases before goin forward

 

[Deets066]

Small piece off the crown too. Stuck the ring and piston clipped the ex port?

 

[Brush Ape]

he shoots he scores

 

[Chainsaw Jim]

I suppose you'll love hearing this..
It's likely the bearing cage let loose, ate the seal and burned up the saw. Hopefully it isn't the case, but it is one of the known problems for what seems like the earlier models.

 

[jmssaws]

I have one from the same place as deets that looks just like it.
I believe they all were gassed

 

[paragonbuilder]

I'm interested in what you find...


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[jmssaws]

The auto tune will compensate for a big airleak and there scored on both sides.
Straight gas for 500 alex.

 

[jacob j.]

I also would say straight or old gas. I've pulled about twenty of these apart over the last three years and have yet to find one with a bad seal or a blown crank, so I would say the auto-tune is doing a good job for the most part keeping the engine together. Out of the twenty- I have found five or so with a blown main bearing, usually on the PTO side. None of the twenty have had a compromised base gasket but several have had bad compression releases. In several I've found the ring locating pin has come loose and caused significant problems.

That looks like old gas scuffing to me.

 

[Four Paws]

Nice candidate for the Christmas saw...tear it down to the cases and do a play-by-play!

 

[Deets066]

I might port this one and the 036, then see which one will go to the Christmas giveaway

 

[Deets066]

I was suprized how fast you can have the whole intake and jug out in one of these saws

 

[Simondo]

View attachment 36824

Small piece off the crown too. Stuck the ring and piston clipped the ex port?

Those two crescent marks on the piston top ? and then a single crescent mark on the piston lip ?
Early ones didnt have the extra bolt in the case and the cooling mod in the top cover..they got hot !

 

[Tor R]

I was suprized how fast you can have the whole intake and jug out in one of these saws

545/550/560 is probleby the easiest Husky saws I've ever worked on, far faster to put together also compared to 346/357.
It's tight, but when I learned the technique with carb/airfilter holder I have to admit it's easy to love those saws.

 

[Chainsaw Jim]

I'm curious what made that perfect little partial circle mark on the edge of the crown. Homemade piston stop?

 

[Deets066]

I'm curious what made that perfect little partial circle mark on the edge of the crown. Homemade piston stop?

Could be, not sure really. I was thinkin that maybe the ring stuck from being scored and it caught the ex port. But hell I don't know

 

[johnny5ny]

Autotune will definitely mask an air leak, even a big one as jmsaws said.
Ive heard of a few leaky decomps on these saws so it might be worth a look, but that piston looks like there's more than just that going on.
Without a doubt, port it while your in there. Even if you don't touch the intake or trans, with a raised/widened/squared exhaust and MM, it's a different saw.

 

[Deets066]

Autotune will definitely mask an air leak, even a big one as jmsaws said.
Ive heard of a few leaky decomps on these saws so it might be worth a look, but that piston looks like there's more than just that going on.
Without a doubt, port it while your in there. Even if you don't touch the intake or trans, with a raised/widened/squared exhaust and MM, it's a different saw.

Even if I wanted to grind on the intake....not really sure where I'd start lol

 

[MustangMike]

It's a Batman saw!!!

 

[Deets066]

I'm gunna light a candle in the jug and set it out for Halloween

 

[RI Chevy]

Leave the muffler off and start the saw. It will look like a fire breather. Lol