McCulloch Super Pro 125c build thread

[fossil]

.021, that’s basically the max you can usually get before they are always open, in my experience

I agree 100% especially new ones, New points will close a thou or so when run in.

I try for 0.019 -0.020" and check them again once they are cinched down. I am not so often after absolute maximum performance/HP but in search of the most reliability including good starting performance.

Mark

Thanks guys.

I had them originally set at .021 and at that gap if sucked the starter handle shaft totally into the starter when I shut it off.

I know I should have pulled some slack out when I shut it off. I think I'll try .019

 

[heimannm]

I have some steel handles for the SP105/125 saws available now. They are a good bit heavier than the original so be forewarned.











I believe they will be quite durable. You might want to make sure and keep your chain tight enough to avoid throwing it as the handle won't be as forgiving as the aluminum.

Mark

 

[PA Dan]

I have some steel handles for the SP105/125 saws available now. They are a good bit heavier than the original so be forewarned.

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Mark

On a saw that heavy what's a little more?

 

[heimannm]

You don't really notice the difference with a 36" bar and .404 chain hanging off the end.

Mark

 

[PA Dan]

You don't really notice the difference with a 36" bar and .404 chain hanging off the end.

Mark

I bet you wouldn't!

 

[Bigmac]

You don't really notice the difference with a 36" bar and .404 chain hanging off the end.

Mark

Probably even less noticeable with a 50 inch bar! LOL

 

[Frank bierce]

I have some steel handles for the SP105/125 saws available now. They are a good bit heavier than the original so be forewarned.

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I believe they will be quite durable. You might want to make sure and keep your chain tight enough to avoid throwing it as the handle won't be as forgiving as the aluminum.

Mark

That looks really nice!!

 

[Lee H]

So there is a SP125 on Ebay thats already up to 462.00, Advertised with 85 lbs of comp.
has many cranks, full wrap broken, Front AV support broken. And who knows what else.
Can't believe someone would pay that much for a piece of chit.

 

[Frank bierce]

So there is a SP125 on Ebay thats already up to 462.00, Advertised with 85 lbs of comp.
has many cranks, full wrap broken, Front AV support broken. And who knows what else.
Can't believe someone would pay that much for a piece of chit.

I can’t agree more. It really amazes me, how much people bid these junkers up to...but restored, or really nice examples...don’t seem to go for chit!!

 

[jacob j.]

So there is a SP125 on Ebay thats already up to 462.00, Advertised with 85 lbs of comp.
has many cranks, full wrap broken, Front AV support broken. And who knows what else.
Can't believe someone would pay that much for a piece of chit.

It's only going to get worse as time goes by. There are more and more younger guys wanting to get these saws and parts, and the supply is dwindling fast. What's not helping is the kart
guys that are stealing the saw motors to keep their karts running, and then the *a-holes like me that have hoarded big stashes of these saws and parts. It's happening with all of the big
desirable saws - Homie 3100G, Dolmar 166, Solo Twins, PM 275, etc. It's just as bad on Craigslist here. There was a clapped out old 125 up on the Portland Craigslist recently that sold
for $800. A good-looking 3100G went for $1300 on the Spokane Craigslist a few months ago.

I can’t agree more. It really amazes me, how much people bid these junkers up to...but restored, or really nice examples...don’t seem to go for chit!!

I don't know about that. If it's a saw from a known, reputable builder (like Lee), then people are willing to pay top dollar. I know Lee has gotten good money for his restored saws.

 

[jacob j.]

I got something really cool in the mail this weekend:

 

[jacob j.]

It's an SP block that Terry Ives was able to bore .040" over for me. This block has a cool history - it was purchased early on as a custom block and then sleeved
by Bell Machine Works in Portland, Oregon - a company that re-manufactured McCulloch engines and parts back in the day. They had bored this block up to
.030" over and had ported it. It had substantial wear by the time I got it so it had to go out to .040" over. The piston I have for it is a new Mc101 .040" over slug
that uses the early 9/16" wrist pin and rod (different from the SP pin and rod).

 

[PogoInTheWoods]

You're locked in the groove, dude. Something awesome with every new post.

 

[jacob j.]

Bump - This was a build I did this spring and then had to tear down again due to movement in the clutch side bearing pocket of the block. So it's back up and running with
a different .030" over block and a new 101D .030" over piston.

 

[PogoInTheWoods]

Out of curiosity, would there be a remedy for the slop in the other block? Overbore and bushing/sleeve in the pocket maybe?

 

[jacob j.]

Out of curiosity, would there be a remedy for the slop in the other block? Overbore and bushing/sleeve in the pocket maybe?

That, or I'm thinking of having it welded up and then machined back down. I know a couple of our members have done modern saw case halves that way. Because of the stress the crank and take-off
components put on the block, I don't think liquid sleeve retainer would work here.

 

[Frank bierce]

Bump - This was a build I did this spring and then had to tear down again due to movement in the clutch side bearing pocket of the block. So it's back up and running with
a different .030" over block and a new 101D .030" over piston.

Sounds great!! Looks amazing...wide handle too!

 

[PogoInTheWoods]

That, or I'm thinking of having it welded up and then machined back down.

There ya go. I've used the sleeve retainer with success on an 036, but agree, there would be considerably more stress (and risk of additional damage) involved with your situation.

 

[Al Smith]

I have of course sleeved a 125 block to stock size but I've never repaired a bearing pocket but I don't think it would be that big of a deal .On something like this the set up time will take longer than doing the machining work .If it were myself I'd use a heat shrink fit just like a sleeve .Then if needed hone it to size .I don't imagine a sleeved pocket would ever wallow out .
Being a McCulloch the bearing would be SAE spec and as such it might have a replacement with a teeny bit larger on the od of the outer race .That's only a guess on my part I've never researched it .

 

[Al Smith]

Another thought .I bought an 048 Stihl that had a spun bearing .The cure on that was using a prick punch and in effect internally knurling the metal in the pocket .The bearing was seated with a compound made by Loctite called "press fit " .On a Mac block it's a tight bearing fit but it's not a press fit .