I bought a fzr400 non runner last october, the bike hadnt run for about 3 years, I recently got it running after changing the carbs and the fuel filter but at low revs (1500 and lower) there is a rattle comming from the back of the engine. Has anyone got any ideas whats causing this?
Cheers

Cam chain ???

You don't hear it at higher revs because the it takes up the slack.
It could be the tensoiner is stuck or the blade at the back is ... stuck (or even missing eek) or the blade at the front.

Download a manual from the thread at the top of FZR general (or maybe workshop) and go through the retensioning proceedure. Or if that doesn't help take the cam cover off and check the blades (you might find it easier to drop the engine forward to do this)

I think its the EXUP valve flapping at low revs, but I'm not sure how to check it, any ideas?
Cheers

Sam you can bend the exup vavle cable holder back a bit and see if it quiets it down, if that does the job turn engine off and back on to make sure exup works. if it does not then the bushes in the exup need rplacing and they are not cheap you have to by whole unit.

hey sam i have got the same problem here with mine. i have just made the cable tightr so it open a little bit. not to much tho because it will not run rite at low revs.

I wouldn't adjust the valve to be slightly open.

Check the cables aren't slack or frayed.
Take off the chrome pulley cover. The pulley should have two tongues pointing forwards (closed position) and there's a small hole in the housing behind it.
Put a small screw / nail or something between the tougues and int the hole.
You can alter the slack at the top near the exup servo, udo the lock nuts and adjustto finger tight only.
Do up the locknuts take out the screw / nail and turn the ignition on and watch the pulley open and close. It should return to the same tongues forward position.