Blew up , what went wrong ?

[HELSEL]

Pistons installed backwards have a life expectancy of exactly 3.5 minutes!

The rings might survive a number of cycles up and down but as soon as they rotate past the locating pin it is game over immediately.

Sedanmans guess would be a good one I think.

EXACTLY 3.5 minutes, Frank you sure are getting good!!!


Rick

 

[HELSEL]

I had a wing nut fall out my shirt pocket and swallowed by a ford v8. You usually only do that once is enough!

Like putting a piston in backwords and timing it.



Rick

 

[Dennis Cahoon]

hahahaha!.....Just another no-it-all "Canadian Cull"

 

[Grappletractor]

If everything else is ok, you got lucky. New piston and ring and bob's your uncle!, make sure there are no nicks at the port edges. I had a wing nut fall out my shirt pocket and swallowed by a ford v8. You usually only do that once is enough!

Seriously, what could go wrong if I did just file and sand those nicks and stick her back together again , seriously

 

[bikepilot]

Your port timeing will be different, potentially an issue. The piston skirt will be less able to stablize the piston and may break or develop pre-mature pistion slap......or there's a slight chance it might run and last ok, but I'd buy a new pistion myself.

good luck

 

[rmihalek]

Pistons rock back and forth in the bore due to leverage from the connecting rod. That's why skirts wear out. If you try to use that broken piston, more pieces will break off and a) score the cylinder, b) seize the piston in the cylinder, c) ruin all the bearings, and d) probably punch a hole in the cases.

Quit while you're ahead with this one and get a new piston.

 

[timberwolf]

As the skirt is busted up that far on the intake side, you would have next to no base compression and would likely never get the saw to start or run a low speed.

I find it hard to belive the jug is fine. I would take a close look at the intake port. even a little dammage there will likely meen the jug is toast.

 

[RES]

SEAL Installation

I finally isolated the leak in my 020AV to the seal on the clutch side. I purchased a new seal. I don't have the installation tool but i think I have a driver that will keep it straight. Does anyone have any advice on how to make this installation problem free?

 

[Crofter]

Grappletractor, you might want to get a second, third , and fourth opinion from Gypos camp. They seem to have a lot of luck with salvaging pistons that have had bad experiences!
The top part would seal ok but the skirt is what controls base compression and timing intake. Even if you got it to run it would soon come apart.

 

[stihltech]

port

Looks like variable port timing to me.

 

[Marco]

Scrounge a pyramid reed valve setup off something and it should be fine, not really. I would even get a new piston on this one

 

[Dadatwins]

Here is a picture of a 440 magnum bearing that blew up on me over the past weekend, saw was running great, then I heard a change of pitch in the sound and thought I popped the clutch, a little further digging showed this.