Just installed new muzzy full system exhaust with a one piece header, now there seems to be quite a bit more engine noise (i.e. vale train and lifter noise. ) is this normal because of the thinner wall tubing of aftermarket exhaust ? or have i not tightened the header enough?. I did not want to over tighten and squash the gaskets too much.

IDK?Sorry.

10 ft lbs torque on header bolts

Take a spent towel, roll it up, stick it in the back of the cold engine pipe. Go back up to the bike as far as you can or have someone hold the sound down so you do hear engine noise, not engine pulse.

Remember you just installed a race exhaust system its not going to be quiet any more. Did you use a thin coat of hi temp copper RTV on all the joints.

Its definately valve train noise coming from where the header bolts to the motor, Its a one piece header so there are no other possible leaking joints in that area, thinking i'm going to remove the radiator and start over with the install.

dd if your gonna remove the radiator get 2 jugs of engine ice youll be glad you did, bike will run cooler