Perhaps I could have asked my question differently.

Am I correct in thinking that the XR69 bikes run an engine size greater than 1100cc when they were originally made with a 1000cc engine?

Why is it the case that these bikes can run an oversize engine but the 750cc cannot?

Just to clarify - I am only asking out of interest - not suggesting that Michael Dunlop isn't the fastest rider or that anything outside the regs is OK.

Cheers

Sam