TBM beat me to the post, by a stroll down to the shed
From MB Racing shed :
No problem with gearbox.
The cush drive and rear hub have been lightened.
Changed Primary drive ratio's (new gear).
250 Gear box ratio's close together.
XR400 piston ,not high compression.
Bigger the bore the more reliability you lose.
Cam and ignition changed as in previous posts..
cheers A
Clear plastics now on tank for protection
PS She runs and sounds sic/wicked/awesome