I agree with the other posts!
Don't "hammer" the engine at top RPM.
This is a heavy piston/ flywheel motor, (think bull dozer as opposd to drag racer).
One thing you can do is richen the jets up.
it's lean, (runs hot) from the factory.
It'll add more fuel to the cylinder, cooling it off, plus some more MPH, (not much)
After 1500 miles or so, (about 4 oil changes), it'll be a happy little camper.
Then, open the air intake up and exhaust and it'll go as fast as you need it to!
Enjoy the bike for what it is- A blast from the past!
Joe
What? it's running great?
Hand me a wrench, I can fix that!