ms260 cylinder

[openspaceman]

I have just pulled apart a seized MS 260 and was surprised to find no markings on the cylinder casting, I thought genuine stuff always had Mahle and/or Stihl on them??

 

Also while the engine number showed it to be a later 44.7mm type the piston is 44mm.

 

Any thoughts other than someone has previously fitted an afetrmarket pot?

 

Also interested to see the piston is considerable shorter than the 44mm one from my FS360 but the gudgeon pins are the same.

[spudulike]

I have just pulled apart a seized MS 260 and was surprised to find no markings on the cylinder casting, I thought genuine stuff always had Mahle and/or Stihl on them??

 

Also while the engine number showed it to be a later 44.7mm type the piston is 44mm.

 

Any thoughts other than someone has previously fitted an afetrmarket pot?

 

Also interested to see the piston is considerable shorter than the 44mm one from my FS360 but the gudgeon pins are the same.

 

The Stihl stuff always has part numbers "Stihl" ir "Mahle" on them, the pistons also have distinctive stamps on the crown and usually a crosshatch pattern on the inside crown of the piston.

 

If these are not present then perhaps someone has ground them flat...........or it is aftermarket!

 

The shortness of the piston is probably down to the stroke of the engine and the inlet port timing which is dictated by the skirt length! Short stroke pistons tend to be shorter.

[openspaceman]

The Stihl stuff always has part numbers "Stihl" ir "Mahle" on them, the pistons also have distinctive stamps on the crown and usually a crosshatch pattern on the inside crown of the piston.

 

Thanks for the confirmation

The shortness of the piston is probably down to the stroke of the engine and the inlet port timing which is dictated by the skirt length! Short stroke pistons tend to be shorter.

 

Yes the bores are both the same and whilst I can only immediately find capacities for the later 44.7mm bore ms260 it's 50.2cc so the stroke should be 32mm . The fs360 is 51.7 so while the stroke is longer by 1mm the piston is 36.5mm against 32mm for the ms260

[SawTroll]

A 44 mm bore cylinder /48.7 cc was used at least up to some time in 2004 - maybe longer, with the exception of the "detuned" EPA version for the US market. Those also had a much more resticted muffler, and made 3.2 hp vs. 3.5 on most (if not all) other markets.

 

The stroke always was 32 mm on the 026/MS260.