Motorcycle Repair: 1978 Kawasaki, spark issues, piston rings, plug cap

Question
Bike is a KM100, problem is when its cold it runs perfect wiht a big fat blue spark, but once run for 15 mins it starst to miss and dies. Ga sis mixed at 25:1, new parts are crank bearing, crank seals, piston, rings, points, consendor, just rewired the wires coming form the stator assy to the coil and kill switch. Thank you

Answer
Adam,

when the engine dies, is there no spark?

-Double check your points are clean and
the gap has not closed up.

-It could be a coil failing when hot
if the spark is poor when warmed up.

-The best thing to do is figure out if
it is the spark for sure or a fuel problem.

-stick a good plug in the wire when
it quits and see what the spark looks
like. If you have spark, try spraying
some wd40 into the carb and see if it fires.

-Then you can narrow down the problem.
If it runs on the carb spray, it may
be a fuel supply problem. If not
you may have to check your
ignition coil, condensor, plug wire
and plug cap. Also make sure the
spark plug itself is not to blame.