stihl 201 piston ring specs

[singinwoodwackr]

I have searched and have found zip, even with the SM.
what are the minimum tolerances for rings on these saws?
If what I have is within specs I'll just clean them up and reuse but I need to know what the specs are.

anyone?

 

[hotshot]

Tolerance as in end gap or thickness?

Stihl is very stingy on their rebuild datum, but all air cooled saws bores & pistons are close to the same. Echo CS-400 has a very good service/rebuild manual to reference rings.

Max (reject) end gap is normally 0.020” or 1/2mm, but I would just get new Caber 40mm (cloned Stihl #4147 034 3003) rings at that point. Minimum EG would be 0.008”. Note that there are 1.2mm & 1.5mm thickness Caber rings.

https://www.ebay.com/itm/265142303848?itmmeta=01HWDTAXWEVXX6JEGEFZCTJSHP&hash=item3dbbb67c68:g:cIIAAOSwR5lgL-ZF&itmprp=enc:AQAJAAAA4PQcPiQJjlup52GULicJcuuYl2k7VpnrDpePTjJ+EuVHCktO7D7S6zalwSe6V9RMxyP76eDFJzldRocHxPo3twaAGEp7DFUhk54OT6TQrHz5XFnFY9BRn6ObmI0VtYOmq6xQfXhX0fzmeGXzusXT364B9vqOG3ChY/Nzcry4SJ47AuWUhqKnCogom2yNaMEfnRgsycA6jcIGT0vOWqS4trztIcZZFZxK1wPX5VkoJszAXj3NHz3NxiWeeDwu8WiilSOyUHBTlzLJEWQ7B1HerWfSCUvPTKG4Cgzp2Rxob7HW|tkp:Bk9SR6Teq7rjYw

 

[singinwoodwackr]

Tolerance as in end gap or thickness?

Stihl is very stingy on their rebuild datum, but all air cooled saws bores & pistons are close to the same. Echo CS-400 has a very good service/rebuild manual to reference rings.

Max (reject) end gap is normally 0.020” or 1/2mm, but I would just get new Caber 40mm (cloned Stihl #4147 034 3003) rings at that point. Minimum EG would be 0.008”. Note that there are 1.2mm & 1.5mm thickness Caber rings.

https://www.ebay.com/itm/265142303848?itmmeta=01HWDTAXWEVXX6JEGEFZCTJSHP&hash=item3dbbb67c68:g:cIIAAOSwR5lgL-ZF&itmprp=enc:AQAJAAAA4PQcPiQJjlup52GULicJcuuYl2k7VpnrDpePTjJ+EuVHCktO7D7S6zalwSe6V9RMxyP76eDFJzldRocHxPo3twaAGEp7DFUhk54OT6TQrHz5XFnFY9BRn6ObmI0VtYOmq6xQfXhX0fzmeGXzusXT364B9vqOG3ChY/Nzcry4SJ47AuWUhqKnCogom2yNaMEfnRgsycA6jcIGT0vOWqS4trztIcZZFZxK1wPX5VkoJszAXj3NHz3NxiWeeDwu8WiilSOyUHBTlzLJEWQ7B1HerWfSCUvPTKG4Cgzp2Rxob7HW|tkp:Bk9SR6Teq7rjYw

No, the depth measurement. I guess I had seen a tolerance spec sheet for something other than Stihl in a service manual

 

[singinwoodwackr]

Tolerance as in end gap or thickness?

Stihl is very stingy on their rebuild datum, but all air cooled saws bores & pistons are close to the same. Echo CS-400 has a very good service/rebuild manual to reference rings.

Max (reject) end gap is normally 0.020” or 1/2mm, but I would just get new Caber 40mm (cloned Stihl #4147 034 3003) rings at that point. Minimum EG would be 0.008”. Note that there are 1.2mm & 1.5mm thickness Caber rings.

https://www.ebay.com/itm/265142303848?itmmeta=01HWDTAXWEVXX6JEGEFZCTJSHP&hash=item3dbbb67c68:g:cIIAAOSwR5lgL-ZF&itmprp=enc:AQAJAAAA4PQcPiQJjlup52GULicJcuuYl2k7VpnrDpePTjJ+EuVHCktO7D7S6zalwSe6V9RMxyP76eDFJzldRocHxPo3twaAGEp7DFUhk54OT6TQrHz5XFnFY9BRn6ObmI0VtYOmq6xQfXhX0fzmeGXzusXT364B9vqOG3ChY/Nzcry4SJ47AuWUhqKnCogom2yNaMEfnRgsycA6jcIGT0vOWqS4trztIcZZFZxK1wPX5VkoJszAXj3NHz3NxiWeeDwu8WiilSOyUHBTlzLJEWQ7B1HerWfSCUvPTKG4Cgzp2Rxob7HW|tkp:Bk9SR6Teq7rjYw

Yea, these are at least .020 for end gaps, probably more, via eyeball. $14 later…new rings on the way

 

[hotshot]

Ok, you can’t beat new OEM or Caber rings.

There’s likely no issue with the rings beam depth if parts are original Stihl. Have had aftermarket Forester 44mm rings be too deep to work on an 031, but fit an 041 piston just fine.