Simply contact me and I will replace with latest edition shaft, bearing, and adapter plate. Simply use a little valve grinding compound on the tapered crankshaft end and the inside of the new shaft to mate them together. If you don't have any valve grinding compound, let me know and I will include a small container with the upgraded parts.
Your drive is one of the early prototypes, we produced about 60 of the version you have and yours appears to be the only one with issues. All the proto-types were custom made, and some would of course vary slightly [it sounds like your shaft might have been too short]. I am the villian, as I made all the proto-type drive systems, not our normal production crew.
When we went into production, we altered the design and now mount the bearing support under the Q-Matic drive plate. The Q-Matic drive is no longer attached to the bearing support. [see 2 screws on your drive near front bearing]. The current production support is machined to set inside the motor casting, and then "sandwitched" by the main drive plate. This method eliminates the drive plate having any effect on the shaft alignment, when in use. We also reduced the hole size in the shaft to make the long 6 MM bolt a tighter fit.
Please see pictures, and hopefully I have explained it well enough, if not please ask more questions.
Remember all EZ Motorbike parts have a 1 year warranty, and we will make sure you are 100% happy.
Have fun,