my 426 makes alot of ticking/rattling. maby its normal. aslo are raptor660 quad started ticking. thought it was valves but nope. couldnt find the problum so kept driving. then 5 hours lator of driveing a whole blew on the bottom end. what happend was a piecs of clutch plate broke off and got into gears and that what did the ticking and lator caused a 800 dolar repair bill.