Motorcycle Repair: 1987 cr125, driveing, exhaust manifold

Question
this bike runs real good. starts with the first
kick. idles good,  it sputters at high rpms.
when i reach powerband.checked reedvalves,seem ok
not broken or torn.its driveing me nuts trying to
figure this out.bike top end was rebuilt about
6 months ago.i only have about 20 hours on it.
any suggestions will be greatly

appreciated.

Answer
Hi Brandon.

Have you done a check of the intake manifold?  It could have a small leak that only makes itself known when at high rpm's.  you could also have a slightly loose exhaust manifold.  Check those but do not overtighten any lockdown bolts or nuts.

There is also the possibility of a small fuel blockage that is just small enough to cause problems at high rpm's as well.

Start with those and see what you find.

Good luck and ride safe.
FALCON