Aprilia RS125R (97' Reg) - HELP NEEDED!!!!!!

[Rob_Skinner]

I have a 97' RS125R (imported bike). The bike has done exactly 36k miles and I have a bit of a problem with it....(hopefully someone can help me out!!)??

The bike cut out on me whilst I was riding it, I can bump start it, but when I let go of the accelerator it cuts out.

Won't start from fresh, tried seeing if I can get a spark from the plug on the engine casing can't see one....when bumping it, it backfires on me.

I've emptied the tank (as I thought I cld have put deisel in), but is was definately unleaded...changed the plug, starter relay is only about two months old (but surely the relay wouldn't stop it from ticking over after it is bumped??)....Anyone got any ideas what could be up with it and any bright ideas how to cure the problem?

email is rob@basement-studios.co.uk thanks for your help.