hi guys, I have a 99 model f4 which only gets used on trackdays, its got a huge flatspot @ 5/6k ,its running standard pipes with an open end can but fitted with a decibel killa
I ve been advised by fellow rider that his f4 was like night and day after fitting dynojet kit but didn't say what stage kit
im torn between stage 2 or 3 ? anybody got any experience on this ?
the bike gets thrashed but im not chasing big power just smoothness , thanks chris fattaff

 

Have you had the carbs set up professionally as I have one and there's no flat spot and I do trackdays as well. Granted there's low power, but that's 600's and they don't open up until 8k, however no flat spots. I'm running the below spec as well, I'd not bother, you'll barely see any power gain at all IMHO.

 

Get the Dynojet kit. You'll use it to tune the carbs, via air needles, mixture screws, and your jets (and really, its the adjustable air needles that you can't piece together on your own).

Since you don't have too many mods, I'd go with the basic kit (with the adjustable air needles), and follow the instructions. There is also a site called Jets R Us, that sells individual jets should you feel the need to change your idle jets and whatnot.

Learning how to set up and tune your carbs is a huge skill you need to master if you want a carb'd bike for track day use.

 

i ve not had carbs set up by pro, nearest dyno about 45 mins away from me at bridgend not far from u pug
I wouldn't take potentially dirty carbs on dyno (waste of £50) to me so I was gonna strip and ultrasound clean them first and if im inside them then surely dynojet is the way to go,i had superb results on my ducati with mikunis
geezer at pembrey was most insistant that if he cud chose one mod and one mod only then it wud be dynojet !
u mite have seen him at pembey pug? he has white san carlo replica all track ready
think I might go for stage 2 then methinks ? thanks for advice guys

 

only one dynojet kit available in uk for the fx-fy model, bought the kit , fitted it , put cbr on dyno , 112-115 bhp at crank, happy days !! job jobbed !!