DT 80, spark yes, but don’t jump on! What is this?

Hello , I have a Yamaha DT 80 ,53 V I have new fuel inside a new battery and a new spark plug. The ignition spark is available but the engine does not start even with start pilot. I think that the ignition spark is not strong enough, can it be? Who knows advice and can give me tips? Thank you very much in front of you.