The insurance company will requie proff that the motorcycle was repaired with the proceeds of the check before htey will even consider working with you on this.
You would probably be surprised how many people intentionally cash these check and naever have the reapirs made.
This is done to propetect the loss payee or the lender. If repairs are not made and the vehicle repossessed, they cannot recover the outstanding amount of the loan, only slavage value, if any.