Thanks for that it's a twin so rocket gold star it is are the rules for pre 60 same as pre 75 suspension wise ie 4 at the back and 7 at the front and can I fit aftermarket shocks ( have a spare pair from a cr 250) and can anyone recommend any forks regards Martin
Yep, 7 and 4 is the go, but before you get started on the bike have a look on the
www.ma.org.au site, read through the Manual of Motorcycle Sport, particularly chapter 16 for classic mx rules, and 16:15.7 for pre-60 rules. No point knocking something up, then finding out it's not compliant. There are several threads on this forum based on little else, and there's a long history of people turning up with bikes outside the rules who have left cursing and not returned.
Should be a good weapon though Martin, a big twin sounds great in a vmx field. Best of luck with your build.