four suggestions
1) is air filter clean?
2) have you changed the fuel filter?
3) run some injector cleaner in the fuel
4) check the OVP relay - I believe it also is a rev limiter (doubt if problem - but maybe)
I take for granted that your spark plugs and distributor cap and rotor are good. If all the above does not help - check the output of your coil. - sorry I lied - FIVE suggestions