hi there my name is Ben. i have a 96 cbr that has been set up for stunting. it has a 60 tooth rear sprocket and has no fairings. i bought it as is and it ran great for about 3 days then one day i was on the interstate doing about 65 or so and it started breaking up it felt as though i was turning off then back on again. so i brought it home for the next few days it would do a little here and a little there as the days went on it got worse.

as of now i have:
replaced the plugs
cleaned the plugs again
new carb holders the old ones were really cracked
cleaned the carbs

so please help me out here it sux having this bike that i cant ride!!!!!!!!!
thanks ben

 

does your fuel pump work? if no, look into that too. they can cause issues like what you describe.

 

Could be electrical. I'd start by checking the wiring in the kill switch.

 

Might as well pull your seat off and see if there's any scorched wires at the harness going into your regulator/rectifier. That's a notorious trouble spot for F3s.

 

fuel pump is not hooked up but it ran fine without it i didnt see any messed up wires by the rec but i will dig deeper
i will check the kill switch have not done that yet

everyone that i have talked to about this said to check the carbs
could these be caused by unsynced carbs?

thabks for the help

 

I think HR was onto it. Without the fuel pump hooked up, the carbs will only have fuel that has gravity fed into them. It may run without the fuel pump at low speeds, Even a few high speed runs, but as soon as you up the rpms, there is more fuel being pulled out of the carbs than what is being put in. You have 4 carbs that need fuel and a gravity system will not be sufficient. Since your bike is running a very high rpm at 65 due to the sprockets, I would guess thats your issue. the person that stunted it before you probably only made low speed runs with it. thats why the issue never became apparent until your higher speed run.

as far as unsynced carbs, I would think your issue has nothing to do with the sync. An out of sync carb will still perform fine at high rpms, its only at low rpms where an out of sync carb becomes an issue.

 

Your first mistake was buying a stunter for your daily ride.[sm=icon_beat.gif]

 

its not a daily its a toy but i would still like to be able to ride it.....

but anywho my only prob is that it ran fine with out the pump when i first got it......?

and it also is ok when u get on it really hard but when u just try to cruise that is when it starts to break up i have tried to do 40 in 4th 5th and 6th it dose it in all of the gears so and different rpms...

thanks again for all of the incite i am going to get a chance to work on it tomorrow so ill keep u posted

 

i got a chance to work on it after cleaning the carbs and puttin on new carb holders it wont start now it........

it has spark i checked all of the plugs and the wires the plugs are fowled so i am going to replace them soon

i am ordering a new fuel pump as soon as i can afford it

i checked the kill switch and the rec wires and both seem to be fine. now dont get me wrong this thing has some wires that are not plugged in seeing as how there is no gauge cluster on the bike but all of the wires going to the kill switch and the rec are ok

so i am completly and otterly stumped!!!! i am a teck at a local tires plus and this freaking thing has me stumped so if u guys would continue to help that would be awesome thanks again

 

any ideas?