fzr400exup 3en2 exup valve removed , help !

[fzr400nutter]

i have a 1989 fzr 400 exup 3en2 the exup valve had been played with by a jackass who filed the valve for whatever reason the bike just wouldnt run properly no matter what i tried so i have now removed the butchered valve and cables and as you would expect low to mid range running is all over the shop can anyone supply information on re-jetting ( jet sizes / settings etc ) or any other methods of improving low to mid performance without losing too much top end ? this is not a track bike but i am a fast road rider who would also like to use the bike around town without having to rev the nuts off it !! any help or info greatly appreciated , thanks .

[blackhat250]

Tough call this Fzrnutter". can you not soarse a replacement Valve... would be easier,,,

[drewpy]

DK spares might be your starting point

[fzr400nutter]

hi lads am considering a new valve / cables but will also need the valve cover and cable bracket as the same jackass butchered these also , i have read on other forums that the headers are now too free flowing ( not enough back pressure ) i have a standard genesis 1wg exhaust ( smaller collector box with standard can one piece job ) in going to try this and see if it changes anything if not ill have to hunt down complete valve set up or complete 3en1 or 3en2 exhaust but the trouble with that is every factory fzr exhaust that ive come across has either rotted out close to the head or the valve is either missing or messed up too !!! i also have a genesis cdi that im going to try , ill keep you posted as to how these experiments go thanks for your suggestions , im a stubborn git and this bike wont beat me i will get it running right one way or another , the bike will just have to learn who the boss is !!!!!