There's no way it's normal. I don't notice it when it's just running and revving. But when it's under load, it's horrible and as soon as it gets above about 3k, it kind of throws you back and then runs fine.

It doesn't feel like it's getting choked out at all. Mine does it with just a tiny bit of throttle so it's not like I'm completely twisting it as soon as I take off.

There has to be a fix for this if this many people are having the same issue.

 

My bike is doing the same thing and can't figure out the exact issue either. But I wanted to ask all the riders with the same issue if they notice a petcock leak? Three main things is spark, compression, and fuel/air. I have fixed my electrical, checked my compression and know I get excellent air. BUT my petcock is slightly leaking out of the pressure valve. Im currently fixing that issue and will let you all know if its a sure fix or slight impact on our infamous cbr 3000rpm problem. I have been reading everything I can about troubleshooting this problem and anything that resembles it. To me the putter in low rpms feels(to me) like not the right fuel/air ratio and currently have a petcock issue. I noticed this output almost the exact moment I Relised the petcock was leaking. I think everyone with the issue should check the petcock forums and check their own petcocks and see if this is just me. I could be crazy but I never had this problem before so no one can say its normal. Honestly its a loss in performance. Ill be re-doing the gaskets for the headers and muffler, and fixing the petcock. Ill fill you all in after that tho. I honestly hope this helps.

 

Funny, my petcock leaks too. I took it apart twice trying to clean it out and then stop the leak. It doesn't shut off completely. If I disconnect the fuel line it will dribble out of the outlet even with it off. You think we're losing vacuum because of it?? Air leak?

 

I checked every forum on the pecock issues. you can do a quick fix but it wont last long and should only be used for emergencies. Im gonna see about copying all the posts, fixes, and tips and putting them in a single thread. I will be letting this thread know if the petcock issue is the culpret behind this stupid 3000rpm issue.
Google this item number
16953-MBZ-B51
that is the rebuild kit for the stock petcock and will make the old petcock work again.
This is a after-market petcock that I am checking if works. I plan on using it but if doesnt work out, will try and use the gasket inside it a a rebuild kit for the old.
Gas Fuel Valve Petcock For Honda CBR600 F2 F3 | eBay

Its just cheaper and I am a very thrifty shopper. I will fill you all in as soon as I havemore info.

 

Hey guys... I'm the OP. I'm glad this thread has taken off like this, though I'm sorry so many other peeps are having the same issue as I. I haven't worked on my bike in a while since my new bike has taken priority during the "nice" riding season here in Virginia. I will be back at it in a few weeks I'm sure...

As far as the petcock being the issue, for me, it has nothing to do with it. Mine operates perfectly. My tank is sitting off the bike right now, full of gas and holding just fine.

I'm starting to think it may be caused by the pilot circuit not being completely clear somehow. I really wanna take the carbs to someone with a parts washer that can hook into the circuits and run cleaner through, or with an ultrasonic cleaner. If this issue is fuel related it really seems like the pilot circuit to me. Have any of you had them cleaned by either of these methods? I am worried that just soaking and spraying may not be getting to the area that is causing the problem... thoughts?

 

I agree with the Percocet not being the issue. Because I think you'd notice it more at higher rpms when you need more fuel.

I have a header and really short muffler and I'm pretty sure I might need a jet kit. I emailed dynojet and they said the needles and shine should fix it.

 

Maybe its not the petcock, but I know I cleaned my carbs with a ultrasonic cleaner and had them syncronized. it was like 200 or so miles ago so pretty fresh. my petcock doesnt leak constantly tho. Im sorry I wasnt more presise. when I ride and after sitting for a while it never leaks. but after I ride it leaks out of the pressure release valve right when I turn it off, even if I turn the Petcock off. its not alot of gas, its like a fuel line amount and then stops leaking. Its doing it because the gasket diaphram inside it has a hole in the center and not giving it the right vacuum pressure. and at low rpms is more noticable than high because our carbuerators arent presise on fuel/air ratios when in high RPM's. but they are more at low RPM's. thats JUST a idea tho. I have got the new petcock and will be installing it tonight or tommow. the second I know more I will gladly write back and tell you if I was wrong. more than anything I just want to fix this dinky problem that is annoying as heck!!

 

So I think I might have found the more technical explanation for the 3000rpm issue. Your petcock is a vacuum petcock system and if the diaphragm seal on the inside gets a hole rip or tear your vacuum hose will suck air from the petcock into your #1 cylinder and throw off your low rpm air/fuel mixture. I think this is the issue. I will know for a fact later tonight or tomorrow tho.

 

So I did some modifications to thepetcock finally and put a new diaphragm in it and new sping and another piece off the Petcock I posted up earlier. and the results were promising. I no longer have that stupid putter anymore and have gained back all of the Power i had lost not to long ago.I will be posting what exactly I did and have pics and steps of it all later. I will be riding it tomorrow and do a final outcome and undersanding of it before I reffer it to you all. I dont want to tell you all soomething that is a bad idea. if anyone with mechanic background could write me so I can discuss this with them to see if it is okay to do i would apreciate it. for now if anyone is reading this I DO advise checking your petcock and fixing it if its broken.

 

I had the same stutter that the original poster had. not sure if it was caused by the same issue. Mine was do to a vacuum leak from the Petcock valve because the diaphragm had a hole straight through the center of it. the vacuum leak was causing the loss of power, and because a hole was in the diaphragm it was causeing the vacuum hose to suck tiny bits of gas to go in the #1 cylinder and making it pre ignite in the low end RPMs thus giving me either THE 3000rpm stutter issue or one that imitates the 3000RPM issue.by-passing the bleed off vent hole and replacing the spring and stock diaphragm with parts from an after-market vacuum petcock valve I have fixed the pre-ignition issue and vacuum leak. I have regained my original power and fixed the stutter.

([To the Original poster]You posted in your first post that you cleaned your carbs and removed the gunk from the inside. I did the same by using the sticky forum in the tech section. But I never got the issue from doing so, I noticed this issue about a month ago when I noticed a slight leak in the petcock, the leak was strange and I was lucky to have noticed it. it ONLY accured after I turned off the bike from a ride. And was only close to a fuel line amount before stopping. I could remove the tank and leave the petcock on and it wouldnt leak.)

just food for thought