The Yamaha 250 requires our Giant TurboSwing. Any other size recommendations are out of date. We have had stock on the TurboSwings and have sent out many in the last year. Due to a high volume of backorders, which take priority due to payment information being given at time of backorder, the items have not made it back on our website. If you are interested and the product shows Out of Stock on our website, please call and place a backorder to get your Giant TurboSwing in our next shipment. Thank you!