McCulloch Chain Saws

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MAC Wizards needed

I have read the posts in the “Is this Super 250 too far gone” thread. Does anyone have any fresh tips on how to remove and reinstall a wrist pin without a press on a SP81/PM850?

Also before I crack open the crankcase, does anyone have any thoughts on why the piston rings don’t extend beyond the piston on a PM570 that shows little use and has a piston and cylinder that look good (at least when viewed through the exhaust port)? In my extremely limited experience the piston melts on the exhaust side. I don’t think someone has flipped the piston but they could have as I don’t know the saw’s history. The saw only shows 60 psi (and this is after cranking it with a ½" drill). I have a NOS piston and rings but I would rather just replace the rings if that is all it needs (same wrist pin dilemma). On the other hand if this is an indication that the saw is junk I’ll just use it for parts.

Thanks, Ron
 
I have read the posts in the “Is this Super 250 too far gone” thread. Does anyone have any fresh tips on how to remove and reinstall a wrist pin without a press on a SP81/PM850?

Also before I crack open the crankcase, does anyone have any thoughts on why the piston rings don’t extend beyond the piston on a PM570 that shows little use and has a piston and cylinder that look good (at least when viewed through the exhaust port)? In my extremely limited experience the piston melts on the exhaust side. I don’t think someone has flipped the piston but they could have as I don’t know the saw’s history. The saw only shows 60 psi (and this is after cranking it with a ½" drill). I have a NOS piston and rings but I would rather just replace the rings if that is all it needs (same wrist pin dilemma). On the other hand if this is an indication that the saw is junk I’ll just use it for parts.

Thanks, Ron

I tried without a press and was not successful. A small press is cheap or find a machine shop. Getting the pin back in without a press was no problem. Even heating the connecting rod, the wrist pin still would not move. A small press took less than a minute.
 
How can you identify a Mac 15, I didnt see anything on the bottom of the case, and didnt look like the data plate said 15 :confused:

Any other models that look the same?
 
How can you identify a Mac 15, I didnt see anything on the bottom of the case, and didnt look like the data plate said 15 :confused:

Any other models that look the same?

All the Mac 15's look the same except for some have different
carbs and on some the tanks are black. No other mac's look
like a 15.

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I got in a (or believe to be) a 797 block.
As Lee had mentioned, cylinder with no markings. I assume it would be a new block??? Similar to this.
It has no casting numbers or markings.
Part # 89897 that was on the box.

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