engine work done???
 

so i bought this 03 F4I from a friend in bad shape, did what i needed to get it road worthy, but not perfect yet. it does have an engine swap from the previous owner before him, and now im wondering whats done to it. this morning i raced a buddy with an 09 zx6r from a 50 roll in 2nd gear (hes afraid of launching) so it was just for kicks and giggles i figured id watch him pull away. to my surprise i jump ahead instantly and keep his nose at my tail until we let off at 150ish......all i have is a K&N and scorpion slipon to my knowlage....shoudl this be happeneing with a stock F4I engine??

Possable, the 03-06 600RR's are slower in the 1/4mile then the F4i due to its great low end torque. Also on short straits at the track I'll fly past almost every 600 and some 750's.

ya ive ridden his and it really wakes up around 7k, and mine pulls the whole rpm band.

The F4i's are known for having more torque down low which is 1 reason why stunters love them so much. I know from experience that my F4i had a lot more get up and go from the lower RPM range than my 07 600RR. Once you hit 7-8K thats when the RR wakes up and beats my F4i.

Most everything that has been said has been the exact opposite of what he is talking about. His bike, from midrange and up, apparently beat the zx6R. Obviously, the F4i isn't too bad at around 7-8k rpm. So, im confused on what everyone else is saying in comparison to his experience agains the ninja.

I would think that the your friend driving the zx6r ...maybe he doesn't have as much experience. Cause i would have thought the zx6r would pull away at a 50mph roll on. just my thoughts tho

sounds like the dude you were "racing" sucks at riding. If somebody good was on that bike it would eat the f4i up sorry.

xxreaper487 - My post was referring to this post here.

my apologies. when i first read them, it just seem to contradict things.https://cbrforum.com/forum/images/icons/icon7.gif

No apologies need man, we all good. Just wanted to let people know why I said it cause I hate when people don't read the post then respond with some left field comment that has nothing to do with anything the OP asked and just wanted to say I was not one of those people.