Motorcycle Questions? Ask a Mechanic.
Hi and thank you for your question.
First, I am curious if you carry a lot of keys on your motorcycle key ring. That can cause problems, as in premature wear and failure, of key cylinders. Some other makes and models are susceptible to this as well. You may have already tried this but sometimes you can wiggle the key forward and back as you apply the twisting motion and get it to turn.
Was the bike sitting for awhile or is this a case where it was working fine than the next time you went to ride it, you could not turn the key?