RPM Limit For A 500

[neutral 3]

The beast according to the rev counter, is hitting the limiter @ 5,000 ish rpm, but a look through the old dyno sheets gave a peak power at 6,000 rpm.
It still feels brutally fast from a standing start, but not as quick as it used to be when on the move and flooring it. Any ideas ?

It's was fitted with an Intermotor coil, which I have heard aren't much good.

[PH430]

Looks like an ignition problem.
Please switch back to the bosch coil.

[neutral 3]

Yes, the coil, my thoughts too @ the moment ! I'm guessing my garage fitted a Range Rover coil, but god knows !