Are standered TZR50 revs limited to 9k max

I have a 55 plate (2006 on the log books) TZR50 with the am6 engine and the revs seem to max out at 9k or just under. I have seen posts where people say they are getting 10k-11k+.

So I need to know is the standered coil pack restrict the revs or do they all do the same job.

I have seen 3 differed shape coil packs availible all saying there for the am6. So i don't know if one does a better Job than another or if a coil pack is just a coil pack.

Thanks