DT125R melting pistons?

I've checked the pump and its fine, checked the thromostat in a bowl of
hot water and its fine so i refitted it again. Also noticed that with
the strobe when its doing the knocking thing the flywheel appers to be
moving/jerking back and fourth.

 

If the flywheel rotor isn't actually *loose* and isn't walking around
on the end of the crankshaft, the strobe light is showing you the
timing at which the pressures and temperatures inside the combustion
chamber *allow* a spark to occur. As I said yesterday, this may not
necessarily be when the specifications call for a spark, it's when the
coil can get up enough voltage to overcome compression inside the
engine...

OTOH, an engine will also misfire on lean mixture, when the cylinder
pressure is very low. This explains why you can be climbing a hill in a
car on a hot day, and you don't hear any pinging, but as soon as you
have to let off the gas to go around a slow corner, the engine starts
pinging like crazy on reduced throttle opening...

According to Gordon Jennings' book, "Two Stroke Tuner's Handbook" a
genuine CDI system can produce 35,000 volts at the spark plug gap in as
little as 2 to 7 microseconds. But the term "CDI", meaning "capacitor
discharge ignition" has been used for ignition systems that actually
are nothing but transistorized electronic ignitions,no capacitor
involved at all, and gawd only knows how long it takes for sufficient
voltage to rise in some systems that are claimed to be "CDI" by the
Japanese advertising men...