McCulloch Chain Saws

[rwoods]

Mark,

I have no doubt you put some of your ten series through the paces. I also have no doubt that my kickback breakages are preventable and are my fault; I should add to the list of reasons an overly oily bar and plates.

If I have ever bent a screw by failing to line the tip and the hole up I am not aware of it but I'm not immune from it. However, with rare exception every ten series saw and every used cover I buy has a bent screw. I would hazard to guess that most are due to installation errors as I have seen and bought a lot of busted covers which doesn't happen in a kickback as the nut is driven back as the screw bends in a kickback not outward. I have also seen a lot of wallowed out screw head slots which could be from a misaligned nut.

I have a few adjusters that are so sloppy the tip just barely sticks out beyond the cover and the only way I can really tell alignment is to snug the cover and watch for the bar to move as I turn the adjuster. If it does I am good to go. If it doesn't or the screw gets hard to turn with a loose chain then I know to start over. A longer tip would make it easier to determine if the tip were in the hole before tightening the bar nuts.

I would love a saw mounted side adjuster but that would take more skills to make than I have.

BTW I was serious, if there is such a person you are the MAC Whisperer, making old MACs behave and come to life in your hands. So please keep sharing with us.

The PM8200 is still seating on the ping pong table so it isn't going any where. Unless you say wait, I'll probably order a piston before they become unobtainable.

Ron

 

[joeymt33]

Ron, your inbox is full! Are you going to Terry's GTG?

 

[rwoods]

Ron, your inbox is full! Are you going to Terry's GTG?

I reserved the date with my wife. Right now, yes. But I haven't committed to Terry yet. I wanted to get a kart saw put together and a nice chunk of wood ready but other obligations and the fleabay saw have gotten in the way. The wood is more likely to make it if Terry needs it than a kart saw.

How about you?

Ron

 

[joeymt33]

If work travels doesn't interfere, I will go. I just hope there will be other macs there because when I fire up these bad boys, they will be the only saws around after all the others jump back in their owners trucks.

 

[rwoods]

MACs were few and far between when I was there a few years back. I took my first SP125C although I had to get someone else to carry it due to my then medical restrictions. Unfortunately, unbeknownst to me the spark baffle was almost completely clogged and it wasn't impressive to those who knew how a 125 should run. It would get a different reaction now. Lot of old iron was there. My favorite watch was an old homey. Hot saws were okay - no races while I was there but I think I would enjoy them. Terry is super nice and puts on a good time for all. mdavlee, another AS member and a friend cut and loaded a chunk of the tree that tried to kill me and we hauled it down to give them something bigger to carve. I would like to get the rest of it and complete my revenge but the ground is probably too wet to get to it. I hope you can make it. Ron

 

[joeymt33]

Sounds fun, I'm pretty sure I can go. I do get scheduling surprises sometimes though.

 

[tomscott]

Extending bolt threads...

Did a little thinking today on the bar adjuster question from the last page. The OE screw size is #10-24 tpi. I have no idea what the OE screw strength rating is, but socket head cap screws are grade 8 and probably a significant improvement in strength. You should be able to get them anywhere, and you'd still be able to use the other original parts. The threads might have to be extended a little on the cap screw, but that's not a big problem since small thread dies are inexpensive. Just be sure to use a threading die and not a rethreading die. The latter is non adjustable and made only to touch up rough spots in existing threads. They don't like having to cut full threads and the cutting teeth will normally break pretty quickly if used this way.

Just a caution here... From my experience hardened bolts (Grade 5, Grade 8) are manufactured with rolled threads (not cut, but formed) and have a thread profile that does not match standard cutter shape of the dies. That explains why you can't even generally get a rethreading die to thread onto a brand new hardened bolt, if you have ever tried.

I know any good machinist can overcome these types of obstacles, but I wanted to mention it to the rest of us mortals out here. It can really make someone scratch their head when their brand new die won't screw onto a brand new bolt, much less cut threads.

Also, with rolled thread bolts, sometimes the unthreaded shank will not be the correct size to have threads cut into it.

I would tend to search this great interweb and just find a screw that is threaded far enough. Fillister head is the preferred type for this application as it has the thickest head with the deepest screw driver slot.

I also agree with the bolt being the best failure point, if something needs to break.

 

[buzz sawyer]

9 cube club?

CAD strikes again. My brother called from an auction tonight to say they had an old 2man Mac and asked if I was interested.
I really wasn't but took a chance and told him to go as high as $60. He got it for less.

Model 7-55 161cc.
It doesn't look like it's had a lot of use. Turns over with great compression, fuel had been drained. 38" bar w/stinger installed and it has an extra 48" bar. Check the 3/4" chain - that's a .404 loop next to it. Except for the center of the muffler cover blown out, it's looks complete and original.

Anyone have an owner's / parts manual they would like to sell?

 

[tomscott]

10-10 filter mount modification "fail"...

The other thing I have noticed is even with the new air filter, the moment I place the filter on, it richens up. I think it would really benefit from having a permanently installed "spit-back" plate so the placing the air filter on doesn't change the tune. (Give me a better name for this if there is one.) I have played with installing the filter with the engine running, and the change happens as soon as the center portion of the filter is positioned but the edges are not sealed yet. It is not a lack of air, just a change in the fuel metering due to the filter proximity to the carb.

View attachment 298323

I have it running pretty good now, especially in the cut, but it is difficult getting the idle perfect with the inability to adjust with the filter in position.

So, will the later 10 series "spit-back" plates fit this carb and keep the air filter stud in the right location?

I bought my later style filter mount with the spit-back plate and went about trying to fit it in the air box properly.

For the first attempt I cut the stud off the new plate and I drilled and tapped a hole in the plate for the correct sized screw to become the new air filter stud in the correct location. This was a "fail" because it raised the cupped filter up too much in the back and it would not have sealed. Bending the rear of the plate down for clearance changes the stud angle. No worky.

Second attempt was to just cut off the rear portion of the plate and try use the existing mount under the new one. I played with removing the spacers on the new plate and using thinner washers to gain clearance but still clear the choke. Another fail. There just isn't room to add anything and not change the cupped air filter shape and have the cover fit properly.

After getting over the fails, I decided to just hold the old filter down against the carb while the engine was running and pick up the left side of the filter to make my idle adjustments. The breathing through the filter doesn't seem to change the idle, just simply have a flat surface so close to the carb inlet.

This method is producing consistent results, and I don't feel so bad flexing up the old filter to make the adjustments. Idle is essentially the same once I place the new filter and cover on.

 

[rwoods]

TomScott, I guess you just explained why it seemed I was cutting a new thread the entire length of the bolts I threaded further. I learn something new every day. Ron

 

[7oaks]

CAD strikes again. My brother called from an auction tonight to say they had an old 2man Mac and asked if I was interested.
I really wasn't but took a chance and told him to go as high as $60. He got it for less.

Model 7-55 161cc.
It doesn't look like it's had a lot of use. Turns over with great compression, fuel had been drained. 38" bar w/stinger installed and it has an extra 48" bar. Check the 3/4" chain - that's a .404 loop next to it. Except for the center of the muffler cover blown out, it's looks complete and original.

Bet you are going to have that monster all prettied up and running real soon now aren't you! opcorn:

 

[rwoods]

Buzzsawyer, I would dare guess that a two man MAC that has seen a lot of use has seen more than one owner come and go. I still am taken back every time I see that MAC sales brochure with the single cutter holding one of those saws. Ron

 

[buzz sawyer]

Bet you are going to have that monster all prettied up and running real soon now aren't you! opcorn:

I'm hopin the carb diaphragms aren't a disaster but I have some material to possibly make new ones. Of course, I'll try to get it running first. If it runs good, I'm debating whether to repaint or not.


Rwoods - you know I'll have to try to "one-man" it at least once.

 

[buzz sawyer]

I wonder if the harvester 3/4 x .122 chain will work on this?

 

[machinisttx]

Just a caution here... From my experience hardened bolts (Grade 5, Grade 8) are manufactured with rolled threads (not cut, but formed) and have a thread profile that does not match standard cutter shape of the dies. That explains why you can't even generally get a rethreading die to thread onto a brand new hardened bolt, if you have ever tried.

I know any good machinist can overcome these types of obstacles, but I wanted to mention it to the rest of us mortals out here. It can really make someone scratch their head when their brand new die won't screw onto a brand new bolt, much less cut threads.

Also, with rolled thread bolts, sometimes the unthreaded shank will not be the correct size to have threads cut into it.

I would tend to search this great interweb and just find a screw that is threaded far enough. Fillister head is the preferred type for this application as it has the thickest head with the deepest screw driver slot.

I also agree with the bolt being the best failure point, if something needs to break.

I've not yet seen any hardened bolts with roll formed threads. It takes more power and pressure to form a thread than it does to cut it. You are entirely correct on the unthreaded portion sometimes being a bit large. Anyone with a drill motor and a file or some sandpaper can overcome that though. :msp_smile:

 

[fechtichmac]

1-60

Hi
Finally arrived new clutch +a set clutchshoes with spring new as well.
New clutch already buit in-fits great.
Now the terrible noises at idling are gone .

Regards

Eberhard

 

[rwoods]

I'm hopin the carb diaphragms aren't a disaster but I have some material to possibly make new ones. Of course, I'll try to get it running first. If it runs good, I'm debating whether to repaint or not.


Rwoods - you know I'll have to try to "one-man" it at least once.

To me that would spell HERNIA. Ron

 

[heimannm]

Good news E, have fun with that old saw.

I had my brothers 99 in my shop for a long time, I could pick it up to move it around when needed, but I still can't imagine running it by myself.

I have seen illustrations of men using the big old brutes as one man saws but I have not seen anyone try to run one that way. Hernia or slipped disk would be the best possible outcome I can think off...

Mark

 

[buzz sawyer]

To me that would spell HERNIA. Ron

Can't be that bad, it's magnesium. :hmm3grin2orange: I may take off the stinger handle to balance it out a little better.

Besides, I pick up and move the anvil in the first photo when I need to. Prolly should weigh it some day.

Heading out now to check the cylinder and maybe try starting this this.

 

[barneyrb]

Well after some checking I do have a SP60. If anyone has an air filter cover they could part with I would be glad to purchase or trade........