Anybody have an opinion on what DESTROYED this piston?

[special tool]

i was primarilly talking about cylinder score.

how about a pic of the cyl?.....if you can get youre camera in there lol

as far as the Valve thing.... not all 2 strokes have them.

Pj

Well, I can't get in there, but here you can see the scoring up and down both intake and exhaust ports (same side on these things).
I am throwing in a pic of the small end needles for good measure.:tong

OCR - no valves on these, they are the same as the big saws - as a matter of fact, the bar oil port comes with a plug from the factory, but the case still has the raised "oil" inscription on it.

 

[willie59]

special tool, I think you need to edit your "looking for wife" sign.

"Must have John Deere tractor and barn, and Stihl chainsaw"

 

[special tool]

special tool, I think you need to edit your "looking for wife" sign.

"Must have John Deere tractor and barn, and Stihl chainsaw"

Yeah - you know my wife has one of those wiseacre equestrian bumper stickers that says, " my ass is too big, but I married him anyway".
So I'll be lookin' for a tractor and barn.....

 

[willie59]

Yeah - you know my wife has one of those wiseacre equestrian bumper stickers that says, " my ass is too big, but I married him anyway".

Man...that's just cold!

 

[OCR]

Maybe dropped a valve, then???


ocr

Lol... that was a remark, meant for my ?? friend ?? Squizzy and his FOD (Foreign Object Damage or Foreign Object Debris).

Then, if he said anything about "valves", I was going to feign a compromised password, and somebody using it to make me look... well, ignorant... did it all by myself though... ... lol

Notice the small case and size ocr, it's usually caps. and regular size... oh well, a failed plan...

Serious now though... He's right about FOD, it can be a major problem with jet engines (no valves either... lol) too.

Here's a pretty good link:

http://en.wikipedia.org/wiki/FOD


OCR...



I thought ATCO might "correct" me too... and I had a better plan... lol

 

[special tool]

The Phoenix will rise again.....

 

[sandy]

still quickcuts

We have 6 ts 460s that have a habit of destroying pistons.
the guy who used to repair them has moved on, so now its my turn.
just pulled two down and found as per photo
ring land broken and rings broken up damaging barrels
I don't want to replace pistons and barrels and have this happen again
any advice much appreciated

 

[Squizzy246B]

Sandy, this why I had to go away from Stihl. The only solution is to increase your oil in the fuel mix slightly and change/wash your filters lots more often. As I said above; I carry spare foam elements already washed and oiled ready to go. This way, when we are working them hard it only takes a few minutes to change the foam and get working. Also, increase the amount of oil in the foam, don't squeeze it all out. This is the only way to keep them going.

My Huskies have a much better air filtration system than the TS 460 but you still have to do them regular. A week is a long time when you are working them hard in dusty conditions.

You can either service the air cleaner regular as clockwork or keep on re-building.

The tree lopper guys don't suffer the same problem I think for two reasons:

1) Particle size is bigger so there is less fine dust getting through...and its wood not concrete or stone

2) Those guys clock up so many hours so quickly usually the whole saw is worn out in less than no time.

I got 5 1/2 years out of my last Huskie and I now have the Husky/Partner K1250 (16"). I expect to get 10 years out of it with a good filter regime. Many guys I know don't get 2 years out of the Stihl but they don't do the servicing. A guy that I started off working for has a TS 460 which must be at least 8 years old now. Every Saturday you can see him at the yard cleaning it and servicing the filters.

 

[coolcatman1]

looks like a spun ring to me i dont know how firmiliar you are with two strokes but the rings are stationary on the piston versus a four stroke where the rings are free to spin in the groves of the piston a spun ring means that the ring spun over the keeper pin in the ring grove and by doing so the end if one of the rings caught a valve and broke it off hence leaving a exposed sharp point or that broken piece of the ring got wedged between the piston and cylender wall and went up and down a few times

 

[danhoe]

I started using Amsoil in all my engines best thig I ever did. I have a partner 750 cut off saw, start it it is wide open and still wide open when it gets shut off and Turbo even has used it. Since the oil switch the thing starts easier. My 1995 K 3500 rolls down the road weighing in at 13,000 lbs & 250,000 miles on it I put Amsoil in that it runs cooler and starts easier. After you put it back together put some Amsoil in it you will be happier, by the way this is not a commerical endoresment for Amsoil, lol digger

 

[special tool]

Back together and running like a raped ape.
Going on the cart to cut about 130' for 24" ADS tomorrow.

 

[doctordiesel]

piston

This is a piston from my TS760 Stihl cutoff saw.
My guys rolleyes said that it had merely run its course and died.
The inner filter was slightly off the seat when I inspected it, the outer filters were secure.
But can this be from some dust in small amount of time, OR does this look like regular gas being put into a 2-stroke $1,400 saw?

Either way, the bottom is still smooth, so I am doing the top - I was just looking for opinions.

fuel to lean

 

[chandlermtnsam]

Looks like the mixture was wrong or perhaps no oil at all.