Piston and cylinder inspections

[thompson1600]

Can someone explain in detail how to perform a piston and cylinder inspection on a used saw? I believe this is done by removing the muffler and looking in the port, but what exactly am I looking for? What are signs it's good and what do sign's of abuse appear like? thanks

Tom

 

[bwalker]

If you are looking through the exhaust port the main thing to watch for is scoreing on the piston and cylinde wall. If you can see the original crosshatch marks on the cylinder and the piston is scratch free chances are its in good shape.

 

[jokers]

Or is that.....

no marks in the cylinder walls and the original machining marks on the piston skirt. No marks on the cylinder are always a good thing as far as I know, and a piston worn smooth shows alot of hours on the saw. You also don`t want to see any galled metal, it had to come from somewhere.:jester: Russ

 

[jokers]

Oh yeah, almost forgot. There should be evidence of a full, free floating ring in each groove.

 

[jokers]

And no caked up carbon just waiting to flake off and trash your engine.

 

[bwalker]

No marks on the cylinder are always a good thing as far as I know

I was refering to the original hone marks that run in a circular criss-cross pattern up and done the cylinder wall. On the pisotn I was reffering to score marks caused by seizure or dirt ingestion. The piston may have circular marks running around the piston left over from when they cam ground it. If these are present its a good sign also. When i bought my 036 it had both the original hone marks on the cylinder and the cam grind marks on the piston.

 

[John in MA]

That's about it.

If the cylinder walls are clean and you can see the turning marks on the piston, it's a low hours saw.

It's a high-hours saw if the piston is worn smooth and/or you can see patches in the cylinder that look worn.

If you see grooves and black streaks running down the piston side, it's a damaged saw. You can sometimes get away with re-ringing it if it's not too bad. That's not usually the case, however. The 026 I just bought has grooves, streaks, canyons, and small mountain ranges in the piston side. The rings seemed to be mashed and melted in the their grooves. Not a good sign.

You can also tell what happened to the saw by where the damage is. All around the piston means bad gas or low oil. Around the intake or exhaust ports usually means a lean seize. I think a plugged muffler can sometimes do the same thing.

Oh yeah, one more thing. Make sure the rings are there. My XL-98A was missing one and I found it in the piston face and cylinder head. Don't tell thre saw, but I just slapped new rings in there and kept going. And finally, my 111S was missing the lower ring. No sign of it blowing up, so I'd guess some Swede in the late '70s had had too much vodka with his herring.

 

[jokers]

Too much Vodka?

So John, how much is too much? Sometimes with a fresh batch of lutefisk you need lots! Russ

 

[John in MA]

Too much is when you start forgetting parts in your company's most expensive saw!

 

[eyolf]

Jokers...with lutefisk you use lots of butter and cream sauce. Then strong coffee and cream.

I am a new world Swede, though. I drink Jack Daniels.

Bruce Swanson.

 

[jokers]

Hi eyolf, I am a new world Norwegian, I don`t even like lutefisk! That`s why I would be drinking vodka with it , LOL. Jack Daniels was always my favorite, sometimes straight up, or sometimes mixed with Yukon Jack over ice if you`re in the mood for a sweet drink.

Russ Christensen

 

[eyolf]

JOkers:
Have always had a problem with Yukon Jack, and some of the cousins, like southern comfort.

I think it has something to do with being young, foolish, drinking too much of it, and learning how bad it tastes on the return trip. The details are unclear, however.

Lutefisk is hard to explain. Hardly anyone likes it. I used to eat it at Christmas time, sort of as a test of endurance combined with a cultural tradition (I think the Vikings wouldn't let a new recruit go out with them unless he could prove he was tough enough to eat it or something), but have learned to like it.

My wife thinks my habit of eating it is something like a relative's habit of pulling her hairs out one at a time; I should seek counseling. At $6 a lb for Lutefisk, maybe she's right.

 

[jokers]

Hi eyolf, I don`t know anyone who truly seems to like it, I think it is eaten as a salute to the hardships our ancestors had to endure, LOL. Now smoked or pickled herring, especially with onions, that`s something I can enjoy. As to the Yukon and the other sweeter spirits, I was never blessed? with much of an ability for return trips. The only way it would make it out of my system other than normal metabolism would be with a stomach pump. This isn`t really a plus when you are young and not fully aware of your limits yet. Russ

 

[Dennis]

YukonJack over ice with twist of lime...nothing like a good snakebite!!! Now Southern Discomfort...that just aint right...kinda like that Cutty Sark stuff....yeck....I think there is still some in my cupboard from the first time i ever met Rotax Robert and Eastie Joe from Enumclaw....last March....

Kinda funny how one gets off topic here....but I think all the bases are covered on the inspection issue....Husqvarna does make a piston failure analysis guide, which can be helpful now and then....most dealers have a few copies kicking around....