I have had an ongoing issue with my 96 CBR 600 F3. It will randomly run good, then run and bog down and shut off, sometimes starting up and running like on 2 cylinders.
I cleaned out the jets last year and it ran great the first time i rode it. the next time the same issue.
this year i replaced the regulator/rec because it seemed to have a bad seal. changed the fuel cap, spark plugs and fuel pump..just cause.A couple plugs were fowled. (I sprayed water on the pipes after it warmed up, seamed to only immediately steam off of 2 and 3) It fired right up...all 4 steamed water off the pipes.
2 weeks later I had the bog issue. I go to try a carb sync, 1 was a little low 2 and 3 even but 4 was a little high, but i noticed gas dumping into the #1 cylinder at idol.
I take the carbs off and open number 1 and 2 to compare. the floats seem fine and the pins blocked air from passing in normal position. what else can cause gas to dump into #1?
i'm stumped

 

If gas is dumping then the needle tip is not sealing. It has a rubber tip and it can be very lightly grooved enough to fail. I wound up replacing all the floats and needles to correct my problems. My bike had been apart for several years and the floats sagged over time. The floats are plastic and need to be supported by fuel or they eventually bend.

 

Thanks for the advice, i will change the pins and floats. I ordered the pins, is there a good place to order floats?

 

I found pins on ebay two days ago looking for something else.
4 us $ for pins and 7 or little more for floats

 

I only saw a used float for $10. I would not put a used one in. I found a new float out of florida for $38. I will buy one for now and see if it fixes the flooding carb.
Thanks for the help! cant wait to fix my baby...had her since 98

I was trying to post pics, but it asks for a URL, do i need to host the pics to show the? or is there a way to upload without url?

 

Yes, you need to host the image on the web somewhere before you can post a pic...

 

Ok ill try to host and post soon. I will update when my float and pins come in!
Thanks for the help!

 

I'm thinking about the drain question and i must say I've never opened a Keihin but in other carburetors there's a kind of automatic drain in case the bowl gets too much full. I say that if the pin in the carb doesn't close correctly the gas should drain to the floor from the small tube used to drain carbs by unscrewing the little screw on the bottom of the bowl.
Please correct me if I'm wrong!

 

I have never heard of that. Every time a float sticks on one of my bikes they carb drains down into the intake...

 

Older carbs used to have an overflow. A Dellorto carb on my Bultaco Pursang would shoot gas out of it's body when priming, as it didn't have a choke circuit. EPA regs changed all that. Gas that overflows either go into a cannister (supposedly only for vapors) or it runs down into the cylinder due to location of the carbs these days. It can run out of the carb breathers as well, but by then, it usually has already made it's way into the cylinder.