hello i am new to this site. i got a cbr 600 f3 last year it was running good for a wile. then one day i noticed little vibration, didn't think much of it. this season i started the bike and it run fine with the same vibration but it began to have a small hesitation when i excalorate quickly from stop. so i took the curbs off and cleaned them (THEY WERE CLEAN WHEN I TOOK THEM OFF) when i put the bike back together the hesitation was still there and now if i twist the excelaration handle quick it all most stalls and couple time it stalled all the way out. when it doesn't go out all the way it make a little backfire. it all most feel like their is no fule getting to the cabs. please any help would help thank you.

 

you cleaned the jets out, right?

 

yes checked the jets they were clean how do i know if i need a sinc to get done on it???

 

It would not hurt to have a sync done at all. It probably is a very good idea since you have pulled the carbs and cleaned them.
Also when you twist the throttle and it almost stalls out, is the bike warm or still cold. if it is still cold then just be patient and let her warm up and that problem should go away.

 

i am trying to find some one to help me sinc it, and the stall problem worst when its cold but it is there when the bike worm as well no that much but there. i think it is the mixture or something in the carbs.

 

If you're backfiring, that means TOO MUCH fuel is getting in, or you have a compression or combustion problem. A misfiring cylinder could absolutely cause a strange vibration, but so could a carb that is WAY out of sync.

Get the bike running, and let it idle for a few minutes. Lightly tap each port on the exhaust manifold. Do you notice that one is more noticably cool to the touch than the rest?

Also, pull out your plugs and inspect them. Keep track of which cylinder each one came from, in case only one is bad. Please post pictures of these.

 

do you have anything done to your bike as far as aftermarket? if so, it could be a pilot screw issue. after i put an exhaust on mine and jetted it, there was so much fuel coming into the cylinders that it actually made one misfire and it did make the bike stall every once and a while until i adjusted the pilot screws the next day.

Also, with regards to the sync issue, when was the last time they were synced? rule of thumb is once a year, but i know a lot of people don't follow that.

 

thank you all for trying to help. the bike came with kn&n filter and two brothers exhaust pipe slip on. today i changed all 4 plugs all 4 of them were light brown on the ends well gaped and clean. i put the new once in after checking the gapes. also i have changed the fuel filter and oiled my kn&n filter. after assembling the bike back, i don't feel like anything changed still hesitates and back fires a little. seance i got the bike last year i never done the sink on it. when i got it the bike it ran very nice no vibration or backfires.what is a pilot screw???? and how do you adjust it? i don't have the sink tool. and every time i call any shop they tell me i need to do the hole service don't know why. thank you.

 

i like bikes

 

lol...