ctylerc1995
Well-Known OPE Member
"Porting" a saw.
This is my first attempt of doing any major modifications to a saw. And only the second that I've cut squish on. Any suggestions are welcome. The victim is my MS461, roughly 2 gallon of fuel through it.
Got it stripped down and I was happy to see the amount of oil on the crank, I've been mixing 42.5:1 using STIHL 2 mix (the grey bottles)
The carbon on the piston suggest it's a wee bit rich I guess but I'd rather have that than lean.
Here is the cylinder, started off with about 40 thou. of piston clearance and was right around 185 PSI cold
I roughed it in with a dial indicator then to get more accurate I switched to this gem, that reads to 0.00005 and got it to less than 0.00002 centered, and then got the run out adjusted with the nuts at the cylinder base. When you do this, it's changes the center at the top, so I went back and got it centered again.
I know it's just a saw and these tolerances don't matter that much but I'm a perfectionist when it comes to machine work.
Getting the spin on with a WWII US Navy Lodge & Shipley, this was once on a navy ship, however I don't know the name of it.
No pictures of the cutting process I was too nervous, I turned it around 200 RPM and cut 50 thou. deep.
Next to turn a mandril...
Don't remember the exact size, roughly 2.060" then polished to exact bore size, AFTER cooling because of the size reducing when cooled, which would creat a smaller mandril. This was some type of stainless I used to make pump components for the coal mines a few months back, the only thing I had around 2.5" and long enough.
This is my first attempt of doing any major modifications to a saw. And only the second that I've cut squish on. Any suggestions are welcome. The victim is my MS461, roughly 2 gallon of fuel through it.
Got it stripped down and I was happy to see the amount of oil on the crank, I've been mixing 42.5:1 using STIHL 2 mix (the grey bottles)
The carbon on the piston suggest it's a wee bit rich I guess but I'd rather have that than lean.
Here is the cylinder, started off with about 40 thou. of piston clearance and was right around 185 PSI cold
I roughed it in with a dial indicator then to get more accurate I switched to this gem, that reads to 0.00005 and got it to less than 0.00002 centered, and then got the run out adjusted with the nuts at the cylinder base. When you do this, it's changes the center at the top, so I went back and got it centered again.
I know it's just a saw and these tolerances don't matter that much but I'm a perfectionist when it comes to machine work.
Getting the spin on with a WWII US Navy Lodge & Shipley, this was once on a navy ship, however I don't know the name of it.
No pictures of the cutting process I was too nervous, I turned it around 200 RPM and cut 50 thou. deep.
Next to turn a mandril...
Don't remember the exact size, roughly 2.060" then polished to exact bore size, AFTER cooling because of the size reducing when cooled, which would creat a smaller mandril. This was some type of stainless I used to make pump components for the coal mines a few months back, the only thing I had around 2.5" and long enough.
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