Hello all. I am having a problem with my new 1990 CBR 600 f1. I bought it about 1 and a half months ago, when I bought it it ran ok. Then it got worse. My friend and I have been trying to fix it.

Here is what is going on.

When I start it the rpm's rev up to about 3000 then it will go down to a good idle of about 1300-1500 rpm with in seconds. But as you give it throttle it bogs down and will die if I don't let off, then it goes to a good idle. I can feather it and it will go to about 5000 rpm but it will not hold, it hits it then bogs down and will die if I don't let off the throttle, when I do it goes to a good idle. Some of the time it will go up to around 10,000 or 11,000 rpms, but will bog down not holding on the rpm.

I have recently changed the spark plugs, the old ones were black and wet with fuel showing to much fuel threw the carbs. My friend has been trying to adjust the fuel screws. One screw that is by the throttle cables and 2 screws that are between carb1-2, and 3-4. He just took the carbs home and opened them up cleaned a little gunk out, found that one of the springs was getting caught up he readjusted that, and found one of the screws on the body of the carb missing he plugged it with a different screw. The carbs were cleaned less than a year ago so we figured it was probably not to bad. I do know I have cali. emission crap on my bike and I want to take it all off, i was also wondering if any one knows how to take it off step by step.

Can someone tell me where my actual air/fuel mixture screws are on my carbs, pictures will help.

Please help, This is my first bike and I want to be able to drive it to work and school so my wife has the SUV for the kids.

Thanks to all who help.