Failure analysis

[davidwyby]

Just bought this as a project. It’s looking good. Anyone want to play?

 

[stikine]

Is the bottom end okay?

 

[lxskllr]

I'm not even sure what I'm looking at. Are pistons multi part? I thought they were single piece.

 

[CurSedVoyce]

Ring Broke. Then the piston beat it to death against the head of the cylinder. That is the ring pin sticking out.
Might have swallowed something as it looks like the ring hit the port. Exhaust looks like. Check the bottom end and see if you lost the bearing on the rod or at the wrist pin.

 

[flushcut]

May that saw rest in pieces in a milk crate that Carin is fairing to the afterlife,

 

[Kaveman]

I see that your thing-gummy got fucky-wucky. Bad time, as that means the dohicky is borked. Also make sure to replace the whosit, as those often hinky at the same time.

 

[CurSedVoyce]

Bork bork bork.

 

[Nutball]

At a glance it looks like the piston was mounted backwards. Ring got caught in the exhaust port, or ring ends beat the pin out into the port.

 

[davidwyby]

At a glance it looks like the piston was mounted backwards. Ring got caught in the exhaust port, or ring ends beat the pin out into the port.

Winner

good deal for me, just needs a $30 piston.

Looks like the saw was freshly rebuilt and puked right off the bat. Still has wd40 in it.

Pretty clean specimen. Still has the bellows and such.



@stikine yes, going to circulate some fuel through the bearings to flush them.

Trying to decide whether to port it or just base gasket delete like my last one. Nice n slow n grunty. Can’t stall it. Ported saws blow more Euc dust in my face. Already have a ported one or two in the works…😬

 

[Magnus]

Broken ring cause this if it breaks by a port and a bit stick out and get trapped.
Why the ring broke?
Heat? fuel? over reved?