i have an 02 F4I i love the bike and it runs perfect except when ever i excellerate hard from a stop its like the bike stumbles from 2000-4000. plugswere just replaced and thebike has only 3000 miles on it anyone know what it could be.
thanks

 

What do you mean by stumbles? Do the rpms jump?
If you just mean that it lacks power then that's very normal. It's meant to idle at 1300, and it goes over 13krpm! The power band is well above 6krpm. Sportbikes have high-revving engines, so you need to rev it to feel any real pull. Trying to give it gas at 2krpm would actually bog the engine and might hurt it over time. I would call 4krpm a low cruising rpm, not an accelerating rpm
Rev it up... but be careful, it can pop the front wheel and loop!

 

when i say stumble its like the bike starts to accelerate hard, then its like it hits a flat spot (like theres no power) for a second or two then pulls hard again . hard to explain but that the best i can do.


my brother has a gsxr 600 and his doesnt do this maybe its just cause my nike is older.

 

Ok, sorry to dig out the ancient thread but I'm experiencing the same problems as this.

At 2000 - 3000 rpm I have a very big flat spot. It will start to accelerate from 1500rpm then bog then start to go again.

I've just purchased the bike so I'm not sure what service items have been done in the part. Looking at it I can see that it has aftermarket headers and an Arrow box, other than that its pretty standard.

I tried another f4i before buying this one and there was no noticeable flat stop in the same rev range.

What should I start with first?

 

Welcome to the CBR Forum Paul,

Probably best you start a new thread in the relevant section as this one is, as you say, ancient.

Cheers, SB

 

Hi Sebastionbear
I was wondering about trying to get some sort of cbr bash going so as to get a few Aussie members together and even coax a couple of overseas visitors and possibly get an annual thing going.
Would love to hear your thoughts mate. We are located in Toowoomba and have the ability to put on one heck of a bbq or even a hangi if the opportunity arises

 

If possible, I'd start by installing a entire oem exhaust system. If that fixes the problem then you know its a fueling/tuning issue with the aftermarket system. Otherwise I do all the tune up items first and go from there- valve clearances, plugs, air filter, oil change etc. Also do a throttle body sync.

 

Yea I plan on doing a full service as I'm not sure what's been done. Plugs, filters, oil, valve, throttle bodies cleaned and synced, going to do the CCT and fps as well while it's all open.