having a issue with my CBR - SRT Forums

seltech · 03-26-2007, 12:17 PM

I know theres some bike guys floating around the forums, hopefully someone can start me in the right direction. I have a 2000 Honda CBR 600 F4. During start up and idle operation it runs excellent and smooth, i can rev it right to redline and it sounds and runs great. When the bikes motor is underload its a different story, while crusing in gear, the bike is bucking and bogging, if i try to give it full throttle it bogs out, it eventually will stop breaking up and begin to rev, but around 5k rpms is where it stops and will not accell any higher. Its a carburated motor. Anyone know of any possible fix ideas for what i'm describing? any leads are appreciated.

Jabbit · 03-26-2007, 12:24 PM

how fresh is the gas in there? If it is old, try draining it and adding some Sea Foam http://www.seafoamsales.com/products.htm

I have heard that stuff works wonders, I am hoping it cures the problems w/ my bike, too.

noodles44 · 03-26-2007, 01:14 PM

You could also try searching or posting here, http://www.cbrforum.com/.

I8UBF · 03-26-2007, 03:59 PM

i have the factory service manuel if u wanna buy it. i sold my cbr last year and no longer need the book. anyhow if your floats in the carborator are bad it will give u those symtoms. you also could have a broke or bent needle valve. pm me if u have any ?s or u wanna buy the book

srtvet · 03-26-2007, 05:37 PM

try new gas and a tune up ( plugs and a carb clean ) if that dont work get a american made bike. lol j/k

ninja5611 · 03-26-2007, 05:39 PM

9 times out of 10 its gas/plugs or an electrical problem with the ignition.

morphiusrt · 03-26-2007, 07:16 PM

yea my bike ran like shit cuz my friend put regular in it, never mind if it sat all winter unwinterized.

Pride-In-Precision · 03-26-2007, 07:38 PM

Call my buddies over at Factory Pro! They will fix this problem for you very quickly. Sounds pig rich on the bottom. I personally would lean the pilots, but I would call and get advice first. Ph. # is : (800) 869-0497 If you can spare the cash, and can handle doing those carbs, buy the kit he has. It will put you in awe. He sends me kits for all of my dirtbikes, and I wouldn't use anyone else. Pretty much the only one who dyno tunes every bike and then goes further and tunes it through actual testing. Thank me later, Sean

Roadkill · 03-26-2007, 07:40 PM

i have the same problem with my bike, right around 5k it starts to sputter...buts thats only once in a while it does it

fivetoez · 03-28-2007, 05:16 AM

If you let it sit over the winter.....it's possible that the gas in the carbs has turned to varnish & is gunkin things up....it happened to my carbed bike last spring.

Jabbit · 03-28-2007, 07:23 AM

I cleaned my tank and put in fresh gas and Sea Foam additive and it made a HUGE difference, I would suggest giving that a try. I got my Sea Foam at Pep Boys.

seltech · 03-28-2007, 07:57 AM

I put new plugs in it yesterday and fresh gasoline, added some carb cleaner. Still running like ass. If i play with the throttle it starts to rev, this is usually when i'm beginning to let off the throttle, it just starts to pull like mad. I'm thinking she's running rich. Thanks for the suggestions guys, much appreciated

yorad · 03-28-2007, 08:32 AM

Quote: Originally Posted by seltech

I know theres some bike guys floating around the forums, hopefully someone can start me in the right direction. I have a 2000 Honda CBR 600 F4. During start up and idle operation it runs excellent and smooth, i can rev it right to redline and it sounds and runs great. When the bikes motor is underload its a different story, while crusing in gear, the bike is bucking and bogging, if i try to give it full throttle it bogs out, it eventually will stop breaking up and begin to rev, but around 5k rpms is where it stops and will not accell any higher. Its a carburated motor. Anyone know of any possible fix ideas for what i'm describing? any leads are appreciated.

My guess if you are dying out under load is that you are running LEAN not rich. You are getting enough fuel to keep up the a/f ratio under part throttle but once you open the throttle more under load you're not getting enough gas in there. You would likely see black smoke from the exhaust if you were running that rich too. I hope you only put a little of the carb cleaner in there! Remember that was designed to mix with "up to 20 gallons" with most brands and you only have a couple gallons.

If it doesn't clear up after a little riding, the main culprits that come to mind are fuel filter, carburetor floats sticking or the needle valves clogged (gas can't flow into the bowl fast enough to keep up under load), but it COULD be ignition too. A weak spark might not be enough to keep it running under load. If it does seem to be running rich or spitting some black smoke then spark seems slightly more likely. Check your plugs and work back from there.

This would be a unusual but not unheard of so check it... did something nest in your airbox over the winter? It happens! Good luck.

seltech · 03-28-2007, 08:46 AM

good point, no black smoke at all, I took a look when i was giving it throttle. I also pulled up the tank and checked the air filter which appears brand new, very clean in the air box also. I only poured in a little bit of the carb cleaner about 1/4 of the bottle approx. I just spoke with the dealership i purchased it from (MOM's in NH) they said they'll take a look at it for me no charge to let me know whats going on.

fivetoez · 03-30-2007, 05:56 AM

If the carbs are all varnished up w/ bad gas........the ONLY way to clean em, is to remove the bowls & drain em out.....adding fresh gas to the tank will NOT fix the problem.