Mcculloch 797, Super 797 thread

[Lee H]

Has it eaten yet?

Yes it has. Gonna get a little more run time on her and shoot a video. Still brakin her in.
But she is a cutter fo sho

 

[JT78]

Excited to see the end result.

 

[Lee H]

So back at this 797, Although the saw saw ran great i was not happy with it's performance. It didn't have the
power it should. I have rebuilt and restored many of these and know how they should run and cut, This saw
didn't have it. I dug into it a couple times checking point gap etc. I felt the compression was not quite there
as the decomp pin was loose in the cylinder but not as bad as the block i got with the original deal. I felt it
was leaking so i found another good cylinder from a well known member here "Thanks" with a nice bore and
decomp hole. Since the new block was standard bore i felt it would be good to bore it. I had an .008 over piston
from Terry Ives in stock so off to the machine shop we go. Got the block back and tonight i got it assembled.

I'm also making a change with the reed valve, although i had put a new one in it i didn't like the way it sat on
the reed plate. So i did some digging and found a new SP125 reed and reed stop. I like this setup better as i
think it will allow more flow. All i had to do is drill 2 small holes in the reed stop to mount it.

 

[Lee H]

Hope to have it together by the week end and do some test cuts.

 

[JT78]

Hope to have it together by the week end and do some test cuts.

I'm sure it will be a runner by the time you are done with it. The one I ended up with that you built is a beast.

 

[Bigmac]

So back at this 797, Although the saw saw ran great i was not happy with it's performance. It didn't have the
power it should. I have rebuilt and restored many of these and know how they should run and cut, This saw
didn't have it. I dug into it a couple times checking point gap etc. I felt the compression was not quite there
as the decomp pin was loose in the cylinder but not as bad as the block i got with the original deal. I felt it
was leaking so i found another good cylinder from a well known member here "Thanks" with a nice bore and
decomp hole. Since the new block was standard bore i felt it would be good to bore it. I had an .008 over piston
from Terry Ives in stock so off to the machine shop we go. Got the block back and tonight i got it assembled.

I'm also making a change with the reed valve, although i had put a new one in it i didn't like the way it sat on
the reed plate. So i did some digging and found a new SP125 reed and reed stop. I like this setup better as i
think it will allow more flow. All i had to do is drill 2 small holes in the reed stop to mount it.


View attachment 315570 View attachment 315571

Did the other block have a kart piston? Looks you are this time?

 

[Lee H]

Did the other block have a kart piston? Looks you are this time?

Yes same piston but this one is .008 over the other was .040 over.

 

[Lee H]

This saw is up and running. Made a few cuts today and a noticeable difference.
Gonna run it some more tomorrow and do a video.

 

[Frank bierce]

Good looking saw Lee, glad you are happier with the performance now. Can’t wait to see it eat.

 

[Lee H]

 

[RI Chevy]

Nice Lee! Such a cool sounding saw.

You got that 881 running too? Be cool to see a comparison cut.

 

[Frank bierce]

Sounds great Lee!

 

[jacob j.]

Very nice Lee - I wish I could make the large-frame top tank saws sound as good as you do.

 

[Lee H]

In the third cut i almost think i hit something not far in the cut you will hear it rev
like it stopped cutting. It didn't seem to cut as good after but the chain looks good.

 

[Hinerman]

In the third cut i almost think i hit something not far in the cut you will hear it rev
like it stopped cutting. It didn't seem to cut as good after but the chain looks good.

What is the difference between the 797 and 125? All I know is they are the same CC

 

[Bigmac]

In the third cut i almost think i hit something not far in the cut you will hear it rev
like it stopped cutting. It didn't seem to cut as good after but the chain looks good.

Ya, you can see that. The saw sounded stronger with each cut, though, your tune four strokes quick unloaded, maybe it slightly dulled the chain

 

[Lee H]

Not sure, I didn't see anything in the wood. It is tuned a touch rich even though
it cleaned out with a load i still think i can lean a hair more. Guess it depends on
wood and bar length. Gonna take a few tanks to seat the rings. I'm happy so far.

 

[Bigmac]

Not sure, I didn't see anything in the wood. It is tuned a touch rich even though
it cleaned out with a load i still think i can lean a hair more. Guess it depends on
wood and bar length. Gonna take a few tanks to seat the rings. I'm happy so far.

Nothing wrong being rich, especially on break in! It just might have slowed down a hair if it was borderline rich and slightly dull, not much just a hair. Still cuts great, and sounds great!

 

[Bigmac]

What is the difference between the 797 and 125? All I know is they are the same CC

They have some similar dna, but are completely different saws. The 797 is a rigid saw and the cp and sp125 av saws. In reality there are more differences than similar part numbers. The 797 is the peak of the rigid large chassis mac, the 125 was the modern version with anti vibe, and a more modern carb, with high idle and locking chock. And with a chain brake option way before it was mainstream

 

[Lee H]

Just arrived today, A pretty original Super 797. It has an HL63E carb on it so i'm assuming
it originally had the HL103 carb which would be an early Super 797. Throttle and choke rods
are correct. Muffler has been welded and the lack of paint on the cylinder cover leads me to
think it may have been changed. but otherwise a nice saw.