jumps down or out?? never heard of bike gearboxes jump down a gear?? if it is that u might have a problem with the selector drum or the spring on the fork that controls the drum, best bet is to take right hand side engine case off n av a look should be able to see it iirc
try reverse shifting, got it on the gixxer, down is up up is down, forgot this at 90 mph suddenly the gixxer turned into a supermoto and i turned into a human poo pile!
