See the below document, refer to pages 6 & 7.

https://www.outdoorking-forum.com.au/images/files/Engine_Parts_List_1999-2006.pdf

There are 2 different part numbers for the flywheel, one specifies the S600.

The below document has changes brought in when the engine was modified by Victa with the assistance of the CSIRO.

https://www.outdoorking-forum.com.au/forum/u...2220/filename/322-PowerTorque2Engine.pdf