Mystery cylinder ID

[singinwoodwackr]

I'm working on a stihl 440 that had been previously tinketed with.
Anyone recognize these markings? 1128 would be correct for a 440 but what might the OS be, oversize?

I got it running but vibration seems excessive.

 

[huskihl]

Some cylinders were marked A, B and C with A being smallest and C being largest. They varied about .002” in diameter and the a b and c helped determine proper piston size

 

[singinwoodwackr]

Some cylinders were marked A, B and C with A being smallest and C being largest. They varied about .002” in diameter and the a b and c helped determine proper piston size

Definitely not an oe part but I’m curious as to who makes this one.
I still need to measure the piston

 

[huskihl]

When you get the cylinder off, take pictures of the clutch side of the transfer port

 

[singinwoodwackr]

When you get the cylinder off, take pictures of the clutch side of the transfer port

No need to remove it so not going to.

 

[rocketnorton]

mighta thought [as did i] you were measurin piston itself

slap might make vibes

 

[Mad Professor]

Definitely not an oe part but I’m curious as to who makes this one.
I still need to measure the piston

Meteor Marks P/C like Stihl.

I'm not sure of 0.002" being A vs B or C big/small. Never had NOS/OEM to compare in hand while having quality machinsts tools, with an A B or C.

I do know NOS/OEM clearances for Stihl saws are ~0.002", on medium size saws. I had NOS/OEM 038S and 038M to compare. A Tecomec (Italy) was 0.0025". These were measured with top of the line Starrett tools (USA Athol Ma) from a Machine Shop.

 

[singinwoodwackr]

mighta thought [as did i] you were measurin piston itself

slap might make vibes

Did that through the exhaust port...came out to 50mm

im still curious as to what AM kit this is.

 

[rocketnorton]

measured bore, not piston
bore-piston=clearance

 

[rocketnorton]

nuff slap can break skirts off
had it happen on dirt bike
125 suz, way back in school days
tryin to be cheap
piston was bout $3. then

 

[singinwoodwackr]

measured bore, not piston
bore-piston=clearance

I was just wondering if it was a big bore kit or ”stock”
I believe the cylinder is aftermarket looking at what markings I can find.
after measuring the bore it is a “stock” 50mm, not a 52.

 

[rocketnorton]

gotcha