I was first caller this time

[old guy]

Checked craigslist last evening about 6:00, there was a 550xp about 45 miles north of me.
Saw was seized, scored but he had new oem piston & cyl, he didn't need the saw anymore so was selling, wanted $145. I called & left message, this morning at 7:30 I left another message, at about 10:00 he called back gave me directions, he said there were 17 calls after mine.
Saw looks great, he said the dealer hooked it up to the comp stuff & there's only 22 hrs on the saw, said his relative ran outboard moter fuel in it. he called Husky & complained about a 22 hr saw being toast & they sent new rebuild kit free, oh yeah, it's mine now!

 

[cus_deluxe]

Wow, you suck! (Pics or it didnt happen)

 

[old guy]

I don't do much with pics and it's all tore down now, it's just a nice clean 550, heck that grey clutch cover even looks good yet.
The old cyl. will clean up too.
All the damage is on the exhaust side, it seems if it were bad fuel the damage would be all around but this concentrated at the exhaust port. Before I run it I'll take it to the dealer and have it flashed.

 

[lwhaples]

Feels good to be number one.At least once.

 

[drf256]

Nice score!

 

[fearofpavement]

I don't do much with pics and it's all tore down now, it's just a nice clean 550, heck that grey clutch cover even looks good yet.
The old cyl. will clean up too.
All the damage is on the exhaust side, it seems if it were bad fuel the damage would be all around but this concentrated at the exhaust port. Before I run it I'll take it to the dealer and have it flashed.

More likely it was run lean than the fuel was "bad". Unless the fuel/oil ratio was off, using outboard mix wouldn't have roasted the saw. Lots of saw failures show primarily exhaust side scoring only (most of the ones I've seen) and a true "straight gas" event is often scored around the entire piston. (and look for bad bearings too). This "overheat" event is also caused by dull chains, overloading the saw and other operator induced reasons.
Sounds like you got a great deal!

 

[Nitehawk55]

Just wondering what the build date is ?

 

[Chainsaw Jim]

I f-ing hate you.

 

[TJ the Chainsaw Mechanic]

I know a thread that this should go in.

 

[Landmark]

Feels good to be number one.At least once.

Or at least a few times.

 

[Mattyo]

I know a thread that this should go in.

Ya mean the dull chain thread?

Need a pressure and vac test on this saw before putting it back in service.

Because it's torn down...we will not be able to get a diagnosis.

 

[Stihlbro]

Awesome find, I have a 550, it is a blast to run. Guy in Tennessee touched it once, it's ran flawlessly ever since.

 

[Mastermind]

Or at least a few times.

Happy birthday.

 

[P.M.P.]

Nice score

 

[Jughead]

Dang!

 

[Stihl working Hard]

Awesome score on the 550

 

[blsnelling]

Could have been a leaking transfer cover or even the decomp. I've seen it happen before. Pressure test before disassembly.

 

[Landmark]

Happy birthday.

Thanks Randy

 

[old guy]

It's a 2013 build, and I will put the miti-vac on it before I run it cuz it sure looks like lean seize to me.

 

[old guy]

I may have found the problem, I pulled both intake covers and both gaskets had breaks in them. I remember Mr. Evans talking about this.
Has anyone put the 550 together sans base gasket? the gasket is .027 thick, I bolted the cyl. down no gasket and squish is .018, will this fly? will also open up the muffler.