no spark on a lifan 125cc

[dadof2]

i have just got hold of a liflan 125cc engine with no spark to replace the 125cc engine that has jamed up on one of my kids bikes

the engine ive got still has original oil not yet discoloured it seems to have been at the beach in white sand with very very little use

ive swaped over all electrical from the plug to the coil ,cdi box ,stator plate ,flywheel and all the wiring ive tried disconecting and replacing the kill switch and still have no spark and its got me stumped
i am hoping that ive done somthing wrong that someone else has come across b4 and any help would be greatly appreciated
cheers

[Weldangrind]

Welcome!

When you say you swapped everything over, does that mean you're using the parts that came with the new engine, or the original parts from the bike?

The first thing that comes to mind is the distance of the magnetic pickup to the flywheel, or perhaps the integrity of the wires leading from the pickup and coil.

[FLASHLIGHTBOY]

FIRST CHECK THE TETher cord at the rear of atv?? does it have one? dis-conect it.. do not jump it.. then check the kil switch.. is it on or off.. remove the black& wire tracer wire in the bottom row of the cdi.. check the wires going to the ignition coil.. one of the should pulse when you turn it over ( hook up your test light from the gound of the battery .. ) it should glow dimmly.. then you have power going to the coil... then you can start to see where the problemn is.. most of the time if the wiring is good.. and youhave nospark.. it is the cdi.. YOU CAN CHECK THE TOP LEFT WIRE GOING INTO THE CDI .. IF IT PULSES DIMMLY .. THEN THE STATOR and pick is good.. please post your results for others to help & learn...

[steelrfn]

That is a great bit of advice about the engine wire, I will be using that.
I recently had an engine that refused to spark unless the coil bracket was grounded, even having a solid ground hooked up to the ground post wasn't enough.... May be worth checking