KZ750 twin engine noise

Hi All - I have a 1977 KZ750 twin with 25000 miles on the clock. It makes a rattly whirry sound on the overrun (that is slowing down from 50 + mph with the throttle closed. I've adjusted camchain carefully and done the shims etc. The engine vibrates very little and pulls like a train. Has standard - fairly quiet - exhausts. Should I be worried? I'm not used to the racket these twins make - yet... Cheers Mike.

Welcome KZRider
Did you check / lube /adjust the drive chain and inspect the sprockets
Dave

If the carbs are not balanced well the primary chain can make a racket, but this is usually only noticable at idle. pretty common on these bikes. Also its possible the baffle in the factory exhaust thats come loose and is vibrating in the muffler.

Hi thanks for replies - yes it's a brand new chain and sprockets. But I should try and balance the carbs properly...  It's definitely an 'inside' engine noise - I'm just not sure its normal or not!
BTW Is anyone else fed up with the robot verification thingy running out after a very short time! Cheers Mike

wrote:

Hi thanks for replies - yes it's a brand new chain and sprockets. But I should try and balance the carbs properly...  It's definitely an 'inside' engine noise - I'm just not sure its normal or not!
BTW Is anyone else fed up with the robot verification thingy running out after a very short time! Cheers Mike

You have 2 approved posts now , so I believe the robot will no longer be any concern 
As a new member  you were not able to post with out each post being oked (Reviewed ) 
That is how we eliminate  spam from our site 
Dave