I have a 1990 yamaha superjet, I have recently taken the engine out to give everything a good clean before summer. I noticed where the shaft that goes to the jet unit couples to the motor there is a little bit of play in the bearing going to the jet from inside the engine bay. Just curious whether it needs a bit of play for when it heats up during use or it is worn and needs a new bearing? Any suggestions would be appreciated? Thankyou