wondering if the zillas are know to vibrate and what do you guys think is wrong with the tranny it shifts up fine clicks through all the gears but when down shifting it doesnt click through them i guess you can say if feels kind of mushy.

 

Do you have the clutch pulled on when downshifting?When downshifting from higher speeds,its harder to downshift without the clutch pullled in.with the clutch pulled in,it should shift down easily. if your talking about when the quad is stopped,sometimes you have to roll a bit to shift certain gears. my 250r vibrates a lot,so i imagine the 500's do as well

 

Never heard of that tranny problem. It's definitely not normal. As for the vibration, the 500's do tend to vibrate. I believe this happens when they are bored and have different piston weights than stock. I have 2 original 500's that have never been touched. They don't vibrate at all. My brother has a 500 that is slightly modified and has been bored 1 or 2 sizes over stock. When he bought it, it had what he thought was a prolite piston. It vibrated like crazy. He bought an original brand (Sunco I think) piston and pin and the vibration when down quite a bit, although it still had a little. The funny thing is that the original brand piston and pin actually weighed less than the one it had in it. Hope this helps.