13,000rpm? Are you crazy?

This is StephenRC45's dyno chart, you will note his bike makes peak power at about 11,700 rpm.
Even an RS250 (on 38mm carbs) only makes (claimed) peak power at 12,250rpm.

Back to the question, the HRC 030 card and the mc21 flywheel togeather give more advanced than HRC thought the bike should have.

The cons of running too much advance?
Well, if the air/fuel mix is ideal it'll possibly denonate and seize.

Really you want to run the least advance you can that still gives the maximium power the engine can. The only place you can do this is on the dyno with a few woodruff keys. £20's worth of bits from Tyga and 3 or 4 runs on a dyno will tell you all you need to know;

Do a power run, fit a 2 degree offset key so the flywheel is further round clockwise than it "should" be, do another power run. That will tell you if the '28 flywheel timing is a better for your engine. If it is you can try going back even further with a 4 degree key and see what that does.
And so on.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread