Seems like the e start on the Wr is what is causing the problem, is that true? If the bikes decomprestion release is not working right then it would put alot of pressure on the woodruff key, when you hit the e-start. Is this the cause? If this problem is not happening on the YZ then I would think it is the cause? Just like when you kick a bike and the decopresion, forces the kick starter to kick back and bite you leg. Just a thought, What is the real problem?