Seized chainsaw

[MossRoad]

Caught the name of the Echo publication on that guy's video. Excellent read. Here's a link to a PDF. Very large, so might take a while to load. I saved it for future reference.

http://texanalovestories.mathisacommonlanguage.com/PDFFiles_/(0005)Engine%20Failure%20Analysis%20Booklet.pdf

 

[RandyT]

Brightened it up a bit.


View attachment 735764

What made me think that the exhaust side is showing is the round hole at the top center above the cylinder skirt could be the hole leading to the carb for the fuel pump pulse.

 

[PILOON]

The best insect repellent: Avon skin so soft lotion. It’s made with citronella oil. Foresters have known this truck for years. Doesn’t work on ticks and chiggers (need Deet for that), but works on mosquitoes and no see ums.

My next door neighbor was the patent owner for Deet* and over a drink he related some research findings.
Vitamin C is a good determent but that can't be patented but orange peels contain lots of ''C'.
Then U can buy effervescent 'C' tablets and drink that B4 going in buggy weather. When it's hot and humid you'll perspire and your skin will contain 'C' and thus deter bugs.

"Avon skin so soft lotion. It’s made with citronella oil,"--- and that further confirms his findings and my experience.

* as director or research for Union Carbide and held some 200 patents.

 

[MossRoad]

What made me think that the exhaust side is showing is the round hole at the top center above the cylinder skirt could be the hole leading to the carb for the fuel pump pulse.

Could be.

 

[MossRoad]

What made me think that the exhaust side is showing is the round hole at the top center above the cylinder skirt could be the hole leading to the carb for the fuel pump pulse.

The more I look at it, the more I think you're right. Those two ports are on the exhaust port side from the pictures of the 570 that I've seen. Would love to see the other side of the inside of the cylinder and the piston.

 

[alexinPA]

I am assuming that is the exhaust port in the cylinder in the picture and not the intake port. The problem is either that is the intake port and the saw ingested a foreign object or the piston was installed backwards at the factory. That piston damage is were the anti-rotation pin would be located which should be installed toward the intake port and would set between the intake port and the transfer port in the cylinder.

This saw is 2011. Was used by professional cutter before i got it in 2016. Was working fine before this happened. Foreign object from where? Fuel line? New cylinder is on backorder... still waiting

 

[Billrog]

Running the saw set to lean will over heat and seize it up also if the muffler is loose and it's sucking air into the cylinder.

 

[alexinPA]

Here's a pretty good video that shows several causes of scoring. The examples he shows all lean towards raw gas (no or not enough oil). Intake side is scored heavily. I'd like to see the other side of the piston.

Interestingly, around 11:00 he talks about the cold seizure we talked about earlier. Not warming the engine before going full throttle. Not the cause in this case, but a cause of piston scoring nonetheless.

Excellent video! Thank you

 

[MossRoad]

This saw is 2011. Was used by professional cutter before i got it in 2016. Was working fine before this happened. Foreign object from where? Fuel line? New cylinder is on backorder... still waiting

A foreign object could be anything. Especially if it was ever started with the air filter off. Or a broken part. Tip of something. Unless you find it, it's all a guess.

Was the piston scored all the way around, or just on that one side?

 

[MossRoad]

Excellent video! Thank you

Yeah, I enjoyed it as well. Shows you there's a bunch of different ways to seize a two-stroke engine. I've tried at least 3 of those myself!