066.....What happened?

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Plan-b

Plan-b

ArboristSite Operative
Joined
Sep 5, 2009
Messages
472
Location
Ontario
This sort of piston damage happens just as the engine starts up from a cold condition, the saw will still run for quite soime time afterwards but the damage has been done. I live in a cold climate, cold for 4-5 months of the year. I have seen many cold scored pistons come my way over the years. The cylinder is cold, it has cooling fins and more mass than the piston. The piston expands more rapidly than the cylinder.

It's cold in NS?
 
Duane(Pa)
Joined
Sep 15, 2011
Messages
2,145
Location
Centre Co.
I posted a thread the other day about de-comp failure. I thought they busted and puked metal into the jug. Most that replied said they leaked and subsequently smoked the top end. IDK? minus 6 seems like a huge red flag to me. Looks like you will have it back in service pretty soon. :popcorn2:
 
chadihman

chadihman

Addicted to ArboristSite
Joined
Apr 12, 2012
Messages
1,984
Location
Pennsylvania
Bottom end is clean as a whistle
this clean?
whistle_zpstj1fe8ce.jpg
 
blsnelling
Joined
Nov 8, 2006
Messages
53,727
Location
Franklin, OH
MAHLE P&C

Saw is extremely low hour.
Untouched since the day it left Germany
That's a shame. I hate these head scratchers when you're not sure what happened.

I had a 045 that seemed to run and tune fine. It turned out to be a crank seal that only leaked enough to cause a problem under extended heavy load.

But as others have suggested, that doesn't look like a heat related seizure.. Really strange. I'd vac test it anyway.
 
Adirondackstihl

Adirondackstihl

Flyz, Fuel & Fotos
Joined
Oct 11, 2011
Messages
5,946
Location
North Country NY
That's a shame. I hate these head scratchers when you're not sure what happened.

I had a 045 that seemed to run and tune fine. It turned out to be a crank seal that only leaked enough to cause a problem under extended heavy load.

But as others have suggested, that doesn't look like a heat related seizure.. Really strange. I'd vac test it anyway.
It's getting all new lines and seals.
 
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