Got mine in the mail today, and started putting it together. The prop kit comes with a plastic hollow shaft, but I think the best thing to do for your motor is to find some 1/8" OD stainless steel tubing. That should hold up better than the plastic shaft. You should be able to take off the set screws and E-clips and get the shaft out with a press or something, then replace it with a hollow one. Hopefully my Yak will be flyable by tomorrow evening...pesky day job!

Carl