True, ask him.
Heavier flywheel? Skid plate?
Some enduros are made for higher average speeds, for racing over semi offroad conditions.
Proper technical stuff could use different shocks and gearing to do better on tight trails.
Maybe a bigger tank, better silencing UK can be funny, better lights ?
I used to run a 250 Montesa MX in enduros in Wales, it was a pig, the close ratio gearbox of an MX means first is too high for tight Enduro work and Top is too low, you scream along flat out on road sections, it would drive you insane.
Welshie
Why are haemorrhoids called "haemorrhoids" instead of "assteroids"?