Ok guys, first off, a pre thanks to anyone who can help me with this issue.

I owned a 95 CBR 900 that was stolen and replaced her with a 99. I have been having an issue though with the 99. Basically when I am in gear and on the throttle it runs great. However, when I release the throttle but the get back on it, there is hesitation and almost a gurgling before it kicks back in. Not that I ever do, but it would make it almost impossible to pop a wheelie with throttle alone. Is this normal? I don't remember my 95 doing this. Some of my friends have said thats the way carb bikes run, but i just don't think so.

Back story, I have replaced spark plugs, have a k&N filter, two brothers pipe and cleaned the hell out of the carbs. I have run Seafoam through them and also synced them up. She has a little over 12K miles on her.



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Well.....I CAN tell you that no.....carb bikes are not "just that way".

Runs good at full throttle.....idles fine.......and runs good at part throttle. What about running at a steady throttle and whacking it open? Will it fall on it's face or take off? (IE.....not closing it and then opening.....just whack it open)
I know.......not much help.

 

Hey dude nice clean bike!

You seem to understand the problem you are having and had done all the necessary things that I will do too. Check out those plug cables too; a faulty one can lead to a misfiring. Besides that I'm not sure your carbs are jetted or not, it might starve for fuel as well; with all the other mods linking to it.

I'm not a wheelie popper guy but check out your sprocket settings; alot of guys recommend a -1 +2 setup for better acceleration and much easier to go up too.

 

I will check the plug wires. Someone else suggested it may be an air leak around the carbs. I am planning a major overhaul this winter so that would be a good time.

Yes, when you are at a stop and just try ripping it, it does bog down and gurgle. It won't "fall on its face" but it does take a second. I have compensated by feathering the throttle on, but sometimes you just need that kick.

Thanks for the compliment. I bought her wrecked and slowly rebuilt using the best parts Ebay had to offer. She isn't perfect, but hey, she is old andI love her! Her is another picture.


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And this was my 95 that was stolen. I hope they are rotting in hell right about now.

 

My 99 does the exact same thing. I'll come up to a corner, u know, downshifting, setting up, and about mid corner when it's time to get on the throttle, she'll bog for just a **** hair and take off. Haven't been able to figure that problem out either.

 

guys, had this same problem, just a little bit worse. i went through everything in my bike, tested all electrical, replaced air filter, plugs, fuel filter(in tank), thouroghly cleaned carbs twice, and still the same. it took a third carb cleaning with 180 psi of air to finally solve the problem, now runs super. you would think it was injected now. as far as your possible air leak, do the spray test. if you dont know how you spray any accelerant(wd40,carb clean,etc.) around all the rubber boots (while bike is running)on each side of your carbs and around your air box(not where the air intakes are though)your motor ilde will rise for a brief moment until it burns the accelerant then will return to normal idle, then you will know where and if you have an air leak

 

I will try the leak testwhen I do my overhaul.

I thinkI may have found the problem though.I won a Two Borthers carbon fiber pipe on Ebay the other day to replace my aluminum pipe with scratches and a little rash. Put the newer one on last night andtook her for a mini test ride. She is screaming now! I will put her through the paces this weekend on our local twisties and see how she really does though. Not really sure howreplacing a pipewould be affecting performance that much but it seems to be running smoother. I guess it was some back pressure issue.

 

hey, gixxereater we have the same bike!