G'day Norm,
I have this problem when the fuel is old ,they won't start without fresh fuel or starter fluid down the carby throat
but once running the motor still runs well on old fuel, I assume that you have tried fresh fuel already though.
I know some new engines in the past were just an assembly of new components that were quickly put
together to ship overseas and once you took delivery of the new engine it would need dismantling and assembling
again . (nothing was torqued to correct specifications or put together correctly)
If it's not an old fuel problem ,I'd be checking for a weak spark ,try another plug , check your air gap on the coil
as I've seen a few new motors and the coil is 1 mm away from the flywheel .I've had a few new coils that were no good as we know , when the ignition coil is failing, which can result in a weak spark at lower engine speeds. As the RPM increases, the coil may produce a stronger spark, allowing the engine to run smoothly once it starts.
Cheers
Max.
