comer 50 reving out high rpms

[luckydog]

hi new here and to kid karting i have a c51 that revs to 11700 rpm on the stand i know this does not count after modulating the throttle a few times at wot it will clean up and rev to 14000+ it has a 58 jet k&n filter ngk bpm8 plug gapped to .027 i thought this might be due to a rich condition so i stepped down in jets it now has a 54 jet when it is cold 160 or less it does the same thing but does clean up sooner when it is hot 180 plus it will rev to 11700 pause for a second and rev out to 14000 has anybody heard this before and how do i just get it to rev straight to 14000 thanks

 

[Familyman]

Why are you going from 58 all the way to 54? not many carbs and engines will run good with a 54, here I try to stay at 57 or 56
Other things to think about what gas and how much oil.
It does sound like it's loading up fuel in the crank case.
180º is not hot for these engines. You want 350º to 450º if you can.