bought a Mk2 two days ago and twice whilst riding hard on the road the engine cuts out and the rear wheel has locked up. The second time I was pushing a ton, a heart stopping moment. Anyone have any ideas, it would be appreciated.

Sounds like a seizure to me. if so then a rebuild is the only way to cure. Trashing from cold is another way to seize and ruin the bike pretty quickly.
Sounds like a top end strip is in order. quite an easy job. Link to rebuild the motor on the homepage

If it was a seizure it was only momentary. I immediately clutched it, slowed down, bumped it and it started straight away. Tomorrow I am going back to the dealer, so he can sort it out.