McCulloch Chain Saws

[leeha]

Sweet 125 Roland.
Those handle braces shouldn't
be to hard to find.
I like the looks of the all yellow ones.


Lee

 

[belgian]

Thanks Lee. All yellow SP's are pretty rare over here. I am glad I have this one in the collection.
Will be on the lookout for a new brace.

 

[Brian13]

Thanks Lee. All yellow SP's are pretty rare over here. I am glad I have this one in the collection.
Will be on the lookout for a new brace.

Real nice lookin SP125. You dont seem to ever see the half wraps over here.

 

[little possum]

Yea Brad, that may just be the case

I think there was one at the last GTG and if I am remembering right, it was a good runner.

It was either IGPOE's or StinkBait's

And 40$ for a 100cc saw? Thats considered a great deal


Nice 125 Roland! You just dont see 125s around here, oneday Ill find one on ebay I guess.

 

[belgian]

Real nice lookin SP125. You dont seem to ever see the half wraps over here.

Half wraps allow you to cut lower on the stump when falling, but take its toll on the muffler paint....It's also easier for taking the clutch cover off and replacing the chain. The saw will roll very easy on its right side when you sit it down on uneven terrain.

 

[belgian]

Nice 125 Roland! You just dont see 125s around here, oneday Ill find one on ebay I guess.

thanks. Although 125's are also difficult to find here, I am somewhat lucky that McCulloch's are not popular in this area, and considered as very heavy, difficult starting saws. That makes is easier for me to collect them and at very competitive prices, and then you get a result as this...

top row : 35A, 35A, 640, SP125, PM105, 15
2nd row : SP105, SP125, SP105, 795L, CP125S, 44super

 

[CM76]

I found a SP125 last week. it was a runner but compression was not the best. So I parted it out to complete a project 125 which I had sitting for almost a year, missing oil assembly and some other parts.

I am very pleased with the result...she has excellent compression and starts on the first pull, sporting a 24" bar.

no full wrap, sorry Randy...LOL

this is what concrete will do to magnesium....it's the only part of the saw that has serious wear.

Really nice SP125 Roland. These old Macs are great saws, plenty of power and big timber history to boot. The half wrap bar is also a nice feature. I came across a 125 with the half wrap bar over here in Australia, and apart from the saws you have - I have not seen another one fitted with the option.

Well done on another nice addition to your collection.

Regards,

Chris.

 

[Brian13]

I need some Mac wisdom!! Where would an air leak most likely come from, with the seals replaced as well as the gaskets. The Super 250 just dosnt seem to want to idle right it either races or wants to die. And on the high idle side no amount of adjustment seems to make a change in the sound. And when it starts to race a bump of the choke will settle the idle down temporarily. This is a NOS carb, so I am thinking I have an air leak. But not sure where to even start.:help::bang:

 

[Roy D.]

My PM 650 has a DJ8J spark plug in it. The IPL I have says RDJ6H. Does anyone know what the correct one is? Do I need more specifics of the model number tag?

I just changed the plug in mine this week. It was the original plug. It was a DJ8J.:greenchainsaw:

 

[heimannm]

You may not want to hear this Brian, but I would suspect the connection between the air box and the crank case. It certainly my require another tear down to check/replace the gaskets if retightening the screws doesn't save it.

Mark

 

[Brian13]

You may not want to hear this Brian, but I would suspect the connection between the air box and the crank case. It certainly my require another tear down to check/replace the gaskets if retightening the screws doesn't save it.

Mark

I bought two of the gaskets that go inbetween the cylinder and reeds. So replacing it if need be will be no problem. I will tighten those down some.

 

[rwoods]

Thin rings vs thick rings

I enjoy reading the developmental history of the SP125C and it has me curious as to the relative advantages of thin rings and thick rings. My gut tells me that thin create less friction but thick wears longer; and thin is marginally cheaper to manufacture than thick. But I can't help but think there is more to it than that as I see Stihl and Husky guys argue over two thin rings versus one thick ring. So what's the Mac story? And are the thick ring versions one ring or two? Thanks, Ron

 

[heimannm]

Thin rings indeed result in less friction and lower reciprocating weight, less "slamming" in the grooves when the piston changes direction.

Thin rings don't last as long though, and are more prone to getting stuck in the groove.

I expect other can contribute additional details as well.

Mark

 

[leeha]

A lot of heat is transfered threw the rings,
Thick rings can rid more heat than thin rings.
Thin rings as a rule will generate more power.
All Mcculloch's i have had apart with the thick
rings there were 2 rings not 1.


Lee

 

[cpr]

The intake configuration is quite different, but if you make a diligent search I believe you will find a thread where someone put an SP125 engine in a gear drive saw and had to make a similar modification.

The D-44 had the third port (as do all of the other saws up through the 795), the 797 and SP105/125 do not have the third port so the intake is different but can be made to fit.

Now, who put that thread together??? Was that you CPR? Maybe it was Leeha?

Mark

Not it. Have yet to put a springy-thingy Mac in the aresenal. Someday. Too many projects right now to add another saw unless the price was impossible to reject...

 

[cpr]

The 797 had a piston with a shorter crown hight and thin rings, part number 67089. This required a longer rod.
The Super 797 uses a piston with a taller crown hight part number 69301 that uses thick rings and a shorter rod.
As Jacob stated in previuos posts you can use some of the 101 pistons as long as you use the corresponding rod.
All 797's that i have had apart "which is a few" have all had the welded crank weights, Not the bolt on weights.
I believe the CP125 had the bolt on weights but i haven't had one appart to varify it.
The CP125 also used thick or thin ring pistons. The thick ring is the same part number as the Super 797 69301. The thin ring is part number 69241.


Lee

Believe this to be so, my S797 has the fattys. They're tired and I may do a straight up r & r, but I am really intrigued by the window port piston JJ talks about...

 

[RandyMac]

This 797 has the thin rings. I'll be taking this one apart, ring gap is at a port.

 

[rwoods]

Thanks guys for the information on my ring question.

The rest of this post may upset the collector/restorer so be forewarned.

I may be delusional but I like to think that up and until the time Mac went to the mass market consumer saws that the changes it made from model to model were meant to be improvements. I have read about the many carbs spec'd but figured that was about supply and demand for parts. What I don't know is when the drive for market compromised matters and how, if at all, did it affect the 125's* and the mid-frame saws. I am sure some would argue that the mid-frame saws were to some degree a mass market consumer saw. But be that as it may be, as some of you know I am piecing together an 82cc saw to use and I am trying to gather the "best" components from the SP81E through the PM8200 (I may even throw in a certain piece off a DE80). In this process, through some error I obtained some thick rings and I was toying with having the piston milled to fit them but I believe I'll leave well enough alone and hope the vendor will get me the proper rings. My next decision point is whether to use the one piece crankshaft or the three piece crankshaft. You are welcome to weigh in on that matter. I truly appreciate all the help you guys have given me from your responses and from being able to read your many posts on Mac issues.

Thanks, Ron

* I like many have a 125 on my wish list. Don't know which one for sure, but they're so scarce I haven't had to face that decision. Maybe one day.

 

[RandyMac]

Have at it Ron.
I'll be piecing together a PM81 with parts from three other saws.

 

[leeha]

Believe this to be so, my S797 has the fattys. They're tired and I may do a straight up r & r, but I am really intrigued by the window port piston JJ talks about...

The window port Jacob talks about,
I believe is a 101 kart piston. I have
one and will most likely put it in a
797 as long as i have the correct rod.


Lee