I am on my 2nd time. I again heard the noise only after about 4 rides since I replaced the key with a yamaha part. I got her all powerwashed up and ready to tear down for the new key. My question is: How many hours is average for the key to last? It seems that my last key only held out for about 8 hours. It is a pain in the ass if I have to do this every 8 or so hours. What is your experience with this? My bike is a 98 yz400.