are you using the right fuse rating?check the owners manual to make sure.ive got a gilera dna 50 and tht takes a 7.5 amp fuse.if it keeps blowing the fuse try a slightly bigger one bt be careful as this cud cause the electrics to fry ,bt sayin tht wen i got my gilera it had a 10 amp fuse in it instead of a 7.5 amp one and it didnt make any difference to the operation of the digital instruments.