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Yes i have jethro. Used a couple of them before and they were both very touchy in my opinion. I do have 1 currently on a pro 10-10 automatic. It seems to be pretty good. It will stay there. The other 2 are in a box. Yes i rebuilt them and tried everything i could think of but i just did not care for them. Not saying they are bad designs, just not my favorites. I agree also that the 37 and 44 are great carburetors to swap onto about any mac. They did things right there.
 
Really like the 37A seems to just have a crispness to it over the other common 65. Not sure why maybe someone does but that's my 2cents. In saying that my 7-10 with the fixed tilly runs real good too. Just tweak the low as lean as it will take n should help a little.
Jethro, I'll definitely try that before abandoning the Tilly - I don't like being defeated...
 
Yes i have jethro. Used a couple of them before and they were both very touchy in my opinion. I do have 1 currently on a pro 10-10 automatic. It seems to be pretty good. It will stay there. The other 2 are in a box. Yes i rebuilt them and tried everything i could think of but i just did not care for them. Not saying they are bad designs, just not my favorites. I agree also that the 37 and 44 are great carburetors to swap onto about any mac. They did things right there.
the 37A are the ones I like to mod for the 125s They do a fine job on the big boys.
 
Here she is the way she will be displayed. The NOS NIB SP 125c came to me in that box with everything but the NOS bar. "I added the bar to the package". One day when I am gone someone will get a chance at a true piece of NOS American Muscle Saw History...
View attachment 1184133
Wait your not going to run it?? 🤣
 
I saw it, thought let it go, then I thought when or where will I ever get a chance at a NOS 125c again? So I pulled the trigger. Wife isn't even bothered about it lol. Let a NOS PM 8200 go a couple years back. I regretted it decided not to repeat that mistake. The 125 came with its original box and all paperwork, tooling and a dawg. There was a time in my life I could not even think of spending money on something like this, I am fortunate I have gotten myself to a place where I can. An America Muscle saw made by arguably the most known saw manufacturer in the world, in an era where America was at her height of industrial might in manufacturing. Nostalgic? Yes. Patriotic? Absolutely. Also fortunate, and grateful. This saw is another blessing to me in an already blessed life.
So glad for you!!
 
This 610 cleaned up nice. Looks better with the spike ! View attachment 1184541View attachment 1184542View attachment 1184543View attachment 1184544View attachment 1184545I assume the little icon above the muffler is for a decomp.
The PM605 (55cc's I believe) & PM650 (60cc same as the 610) used the same clutch cover as the PM610 with the little cut out,but only the 650 had the decomp valve.It was usually needed cause of higher compression due to different & more aggressive porting,tool steel rings vs cast iron ones on the 605 & 610.
 
The PM605 (55cc's I believe) & PM650 (60cc same as the 610) used the same clutch cover as the PM610 with the little cut out,but only the 650 had the decomp valve.It was usually needed cause of higher compression due to different & more aggressive porting,tool steel rings vs cast iron ones on the 605 & 610.
I figured it was due to something of the sort. Thanks
 
PM605600134
1.808​
1.375​
3.528​
57.9​
PM610600133
1.837​
1.375​
3.642​
59.7​

Just for the record, PM605 and variants are almost 58cc, PM610 and variants are just under 60cc...

Earlier models of the 600 Series used thick rings, later models were all thin ring including the 605 and other "3.4" variants.

1719063329949.png

The PM650, 655, and 690 (cut off saw) were equipped with a DSP (compression release valve) located above the muffler. These were dropped on later production and replacement cylinders for some reason. I think the location of the valve became a problem if carbon collected in the port, eventually scoring the piston. This was a problem on PM800 and DE80 models with the DSP located in a similar position.

Mark
 
PM605600134
1.808​
1.375​
3.528​
57.9​
PM610600133
1.837​
1.375​
3.642​
59.7​

Just for the record, PM605 and variants are almost 58cc, PM610 and variants are just under 60cc...

Earlier models of the 600 Series used thick rings, later models were all thin ring including the 605 and other "3.4" variants.

View attachment 1185706

The PM650, 655, and 690 (cut off saw) were equipped with a DSP (compression release valve) located above the muffler. These were dropped on later production and replacement cylinders for some reason. I think the location of the valve became a problem if carbon collected in the port, eventually scoring the piston. This was a problem on PM800 and DE80 models with the DSP located in a similar position.

Mark
Thanks Mark!
 

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