Stihl help please!

[tbone1911]

I have been buying repairing and selling refurbished Stihl saws for about ten years now and have come across a saw that I am having a problem figuring out. I am trying to put a saw together from spare parts from my collection of leftovers. I have a cylinder from the MS 210, 230, 250 series. The cylinder bore measures 42.05 mm. I cannot seem to find a matching piston based on this diameter. I am using a Starett telescoping inside micrometer with a good Mitutoyo digital calipers. I feel like the measurements are very good. Can anyone tell me what piston will fit this saw?
Thanks, Bill

 

[mheim1]

The 210 and 230 should be 40mm bore and the 250 should be 42.5mm.

 

[z71mike]

The 42.5mm piston is 1123-030-2016

 

[AVB]

Just a guess but I think you got a MS240 42MM cylinder.

 

[z71mike]

The 2 cylinders look drastically different. Got a pic?

 

[watsonr]

The 025 piston should be 42mm, really 41.94mm. The 250 is 42.5mm. Use a Hyway piston with Caber rings, I don't think Meteor makes one in 42mm for the 025.
1123-030-2002 should be the right number.