hello ive just bought a 2006 model yzf 250 and there is no spark at all. i have checked all the obvious things like kill switch, plug, ht lead and all the connections but its still not sparking. could anyone tell me what i should look for next and how to check the cdi unit and the coil etc to see if they are working properly because i dont want to go out and buy the bits and it still doesnt work. any help would be much apprechiated. thanks

You will need a multimeter to perform the test to find the problem. You will also need an owners manual for the specs. You're right to start with the simple things first. Unplug the kill switch, check the wiring for loose or broken connections, check the ignition coil's primary and secondary windings for the proper resistance, check the generator coils for proper resistance, check the trigger module for proper resistance. If all of the above test out to spec. with no shorts or open circuits, it is safe to assume that the CDI is at fault. There is no test other than process of elimination for the CDI.

check where the plug goes on the cdi, i had no spark at all, n when i opened it up, it had water in it. after i cleened it, the moto started first kick.