if you just put a expansion chamber on
your moped you will need to increase jet
sizes to keep the motor from seizing up.
if will seize because the fuel mixture will
be to lean to lubricate the rings and piston
wall. go three sizes up on the main jets
for a start.
a properly jetted two stroke engine will
have a spark plug tip that is slightly grey
or brown in color. an overly rich mixture
will manifest itself as a black carbon mess
at the end of your sparkplug. a lean mixture
will have a white tipped spark plug.
ride your moped around after the pipe is
changed and if it acts funny shut it down and
look at the plug. if its making funny noises
be very careful you don*t seize it up.
before ya do all this modifying just ride it
around in stock form. the less modifying the
more reliable it will be </HTML>