Will riding with prolonged speed limiter damage the engine??

[zirconxi_imp]

Well, its a good thing my bike don't have a catalyst. But i think speed cut happen somewhere around 6k-7k rpm, isn't that consider acceptable low rpm for bike?

It is OK to hit the limiter once in awhile, but revving your engine that high on a long term basis may cause wear and damage.

In general, a hard limiter cuts either the spark or more commonly the fuel.
If it cuts the spark only, the unburnt fuel (HC) enters catalytic convertor, slowly plugging it on a long run. HC is the prime killer of catalyst, like i.e. frequent misfire...
Cutting fuel is a better option for engine, catalyst and environment.