Un seizing piston

[merc_man]

funny Al...my "mix recipe" is 1/3 acetone 1/3 ATF 1/3 diesel and 2x the "patience"...time is the key to a "loosener"

Well i was gonna mess with it friday but thought i would leave it till after the weekend. I hope thusnis enough patience lol. If it dont free up tonight i will mix some more ATF and acetone and let sit for couple more days. Im in no rush. Not.like.i need this saw running tomorrow. Just a saw to tinker with.

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[Al Smith]

The key thing is keep your cool .There's a lot of difference between a little tap tap tap with a hammer as opposed to breaking concrete with a ten pound sledge hammer .
My worst was on a Caterpillar pony motor .The block was shot and all I wanted were the pistons and crankshaft .I had to mine for them .Literally carved the block from out around of them .Took forever and about a box full of die grinder cut off wheels .Not to mention the amount of beer .

 

[merc_man]

Well i got it freed up tonight. Does look like some light scoring in cylinder. Hope it will clean up. I cant see how the cylinder comes off. I gotta clean some more of the crud off so i can see better.

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[merc_man]

Found this pic on the web. Looks like cylinder is part of the crank case. May be a harder fix then i thought.

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[Al Smith]

You'll have to clean up the top of the cylinder so you can shove it out the top . If it didn't have a head you'd have remove the rod cap and shove the piston all the way up and rotate and remove the crank shaft and pull the piston out of the bottom .You'll figure it out . Don't loose the needle bearings in the rod .

 

[Al Smith]

That one was made before the pressure cracked rod ends were used and should have markings on the cap and rod for reassembly .If not mark them .I might add pressure cracked rods used on most automotive engines these days were first used by McCulloch motors .--historical trivia --

 

[Philbert]

Well i got it freed up tonight. Does look like some light scoring in cylinder. Hope it will clean up. I cant see how the cylinder comes off. I gotta clean some more of the crud off so i can see better.

Contact @heimannm - he is a McCulloch guru, but may have not seen this thread.

Philbert

 

[Wood Doctor]

I recall years ago when my 1978 Mac 610 locked up. I simply sprayed some Liquid Wrench into the spark plug opening, waited ten minutes, and with two wrenches, it came loose. Next day I started it and it ran flawlessly. The same saw runs today:

These vintage Macs are tough puppies.

 

[Larry B]

Well i got it freed up tonight. Does look like some light scoring in cylinder. Hope it will clean up. I cant see how the cylinder comes off. I gotta clean some more of the crud off so i can see better.

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If it was me I would just use a little scotchbrite on The cylinder then just run it. Unless you are looking to do a full rebuild. I have unseized a bunch of engines and once the engine is unstuck they run just fine.

 

[merc_man]

If it was me I would just use a little scotchbrite on The cylinder then just run it. Unless you are looking to do a full rebuild. I have unseized a bunch of engines and once the engine is unstuck they run just fine.

I think i will have to pull apart. The rings will probly be stuck.

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[Al Smith]

The comment about the Mac 610 is interesting .People bad mouth those things but they are about the toughest saw engine of any ever made .Even with a damaged cylinder these things will run forever .McCulloch sold a zillion of them .

 

[Larry B]

Unless it was carboned up the rings are probably not stuck. You can fill the cylinder with your favorite magic elixir and let it soak for a few days then do a compression test. I like seafoam, I buy it by the gallon. I had a 1957 Locke Triplex with a 8hp cast iron Briggs that set for 20 years. Seized like a stone. Pulled the head and lots of surface rust. Spent a week getting it unstuck and it runs just fine with no oil smoke. Has thousands of hours from commercial use. Still have it as a conversation piece.

 

[merc_man]

Got the piston out. It cleaned up nice. Just gotta do the cylinder. Hope it cleans up just as nice. I havnt played with the rings yet but they are tucked in ther tight. May hit with some wd 40 a few times and loosen them up. Thats what i used to clean the piston up. Kinda excited now. Just not so much for trying to get them roller bearing back in.

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[merc_man]

Oh i did notice the piston seems to have a little play on the one side of the piston pin. Is this ok?

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[merc_man]

Not real good pics. Took a wire scrub pad thing to the cylinder. Looks like it has some scoring. Whats the best way to clean this up?

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[isaaccarlson]

If you got as much out as you could and the cylinder feels smooth, run it. They always look worse than they really are. Any little residue will come out during use. Clean out the ring grooves, oil everything real good, put it together, start it.

 

[Al Smith]

About the needles .Just grease them up and stick them in .The fuel/oil will wash the grease away when it runs .

 

[merc_man]

About the needles .Just grease them up and stick them in .The fuel/oil will wash the grease away when it runs .

Good idea with the greese. Ive done that befor for other stuff but never crossed my mind for this. Thanks.

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[Larry B]

That cylinder looks better than most I have unstuck. Should run fine. I like to use seafoam to unstick rings. About the only thing I use WD40 for any more is to clean and shine up the plastics on customers equipment and a little in the plastic bags I put sharpened saw chains in.

 

[merc_man]

That cylinder looks better than most I have unstuck. Should run fine. I like to use seafoam to unstick rings. About the only thing I use WD40 for any more is to clean and shine up the plastics on customers equipment and a little in the plastic bags I put sharpened saw chains in.

I still have a part bottle of sea foam. Maybe i will soak it tomorrow.

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