Little Mcculloch 797 project

Picked this saw up a few weeks ago on eBay. Have some time today to check it out a little. Looks like it will need a little work. Should be a pretty picture heavy thread.

Muffler shroud hole has been rattled, and ripped through...so a bolt and washer is now needed to hold it in place. (Apparently these saws have some vibes??)


Wrap handle on it, has a pretty bad chain rash hit that needs to be repaired.



Original square muffler?

 

carb box...nothing too exciting here

Some ambiguous piston pics to start with...ambiguous filter pics next
Piston does show a little heat damage will clean it up as best I can...don’t really see any scoring. Will need to get some rings for it

I also see the recessed muffler mating area. Had a quick schooling on the different blocks cp125/125c/101/797 from a fellow member, and as I recalled, the 797 used a copper exhaust gasket?

 

Very cool Frank - the regular 797 IPL shows a full-length copper exhaust gasket, but the Super shows an in-set gasket like your block has. However, the Super shows a thick-ring piston.

So maybe you have a Super block with an earlier piston?

 

Would the super have the boost port Jacob?

 

Mike -

It shows the boost port cover and gasket on the IPL for the super, so I'm guessing so. The two saws I have are frankensaws and I think one
of mine has the CP cylinder, so I've never been able to really discern the actual differences between the super and the regular.

I think Lee is the expert on these - he's rebuilt many.

 

Maybe I’ll get my super 797 out to see what I can come up with, that is different.

 

They both have boost ports I believe Mike.

 

This will be cool Frank! Looking forward to this

 

what are the block numbers Frank?

 

I believe the 797’s got the puck muffler and the 795 got the square

 

Here is the ipl I have downloaded...shows a square muffler.

 

Here is where it sits now.


Looks like the dsp decomp has been leaking for a while. Plunger is very loose, and wallered out

Also noticed the top, where the 125 decomp s are, has a threaded plug


Here are the block numbers

 

Yes indeed! Must be just the supers got the puck? Or just the cp?

 

Also not seeing boost ports.

 

That looks just like my cp block, must be a late super797 block, my cp block has that style exhaust port, but it has the cp casting number on the pto side, have heard the super 797 didn’t always have identifying numbers

 

I’m thinking it may be a CP block.

 

I haven’t had my 797 apart, but dose that block have av mounts on the top of the head?

 

hmmmm, it does not.

 

Then late super 797! It may confirm what many believed, that the late 797 and early cp blocks were super similar! I am curious to see the combustion chamber!

 

here is the combustion chamber.