Re-building Jonsered 621

[saar20]

Hello

I have a old Jonsered 621 and would like to change the piston. I would like to know, can i replace the old one to a newer model piston or mast it be 621 modle piston. When i looked around google, i find this:

New piston rings for 621. Maybe one of the pistons fits in 621.

• RS 51 (1990-06)
• RS 51 (1991-09)
• RS 51 (1992-05)
• RS 51 (1993-05)
• RS 51 (1994-06)
• RS 51 (1995-03)
• RS 51 (1996-03)
• RS 51 (1998-03)

• RS 52 (1999-04)
• RS 52 (2001-05)
• RS 52 (2002-08)
• RS 52 (2006-07)
• RS 52 EPA (2001-05)
• RS 52 EPA (2002-08)

• 525 (Newer Edition)
• 535
• 621

• 2051
• 2051 C
• 2051 W
• 2051 CW

• 2051 Turbo (Serial No. > 302 0001)
• 2051 W Turbo (Serial No. > 302 0001)

• CS 2150 EPA (2004-03)

• CS 2152, CS 2152 EPA I models:
  • CS 2152 WH
  • CS 2152 W
  • CS 2152 C
  • CS 2152 CWH
  • CS 2152 WH

Sorry for my bad english.

 

[Stihl 041S]

Check in the Jonsereds thread in the chainsaw Stickies section
Welcome to the camp.

 

[SawTroll]

Maybe you could start with sorting those "candidates" by piston pin size, to narrow it down? Is there any real canditates at all among the ones listed (it really is quite few, as many of them are the same)? I suspect the answer is negative, as they all are for smaller engines, with a 3 mm shorter stroke.....

Also include 45 mm pistons used by other brands in the search for candidates.....

 

[SawTroll]

Check in the Jonsereds thread in the chainsaw Stickies section
Welcome to the camp.

I would definately do that, if I needed to rebuild my 621!

 

[Cantdog]

No....there are no proper substitutes.... 621 has an old school design motor....piston is domed....all those piston are flat top.....even if you could find a piston with the correct diameter, wristpin diameter and deck height to match the 621 it still would not make the designed compression. These motors were designed to run on high octane, leaded petrol...

 

[SawTroll]

No....there are no proper substitutes.... 621 has an old school design motor....piston is domed....all those piston are flat top.....even if you could find a piston with the correct diameter, wristpin diameter and deck height to match the 621 it still would not make the designed compression. These motors were designed to run on high octane, leaded petrol...

No surprice there.

 

[SawTroll]

How about an 028 super piston, it was said to be domed at another forum - but then there are all the other factors.....

 

[Duke Thieroff]

I have a nice 621 piston available for sale on my website as well as a bunch of other 621 parts.

http://sawsalvage.com/products/jonsered-621-piston-and-cylinder-kit-jug-head-top-end

I would be willing to split it from the cylinder if you were not interested in it.

Chris
Www.Sawsalvage.com