I bought this 2000 cbr F4 and was changing the spark plugs cuz it seems to be running rough when I rev it up a little. I figured a plug could be bad, but I'm not a pro. I know cars pretty well, but never messed with a bike. I notice this toggle switch mounted on the black intake pipe just before in goes under the gas take on the right side. Is it stock or did someone install something I wonder. I didn't mess with it, but maybe it is a kill swich. I noticed some oil on plug number 4 that i pulled out. Maybe the plug got oil fouled, but it is too late now to rev the bike up to see if it is fixed. Just curious bout the toggle switch.

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Dude that is not factory! I dont know what it is. [sm=nxsmile.gif] possibly and a toggle switch for the silenoid. I dont know

 

My first guess would be a kill switch. Depending on where they lived they might have been worried about someone stealing it. Check it out and see where the wires go. Better yet flick the switch and see what it does. It could also be a switch to turn the electric fan on manualy. Some people do this because from the factory the bike has to get pretty hot before the fan will turn on. Just check the wires out and see where they go. Don't be afraid. Hope this helps.

 

Could be a kill switch for the lights. Very handy when trying to avoid the po-po after you've been bad. This mod is typically accompanied by a questionably placed license plate.

 

I found out it is actually a kill switch. So I guess that is kewl cuz i can use it to prevent someone from jacking my bike. But if someone really wanted it they would just pick it up and throw it in a truck. It seems to be sputtering or missing when it is just above idle and below 4k rpm. Could a plug be fowled or could it be a clogged carb? I put some carb cleaner, but i guess that will take time to clean it when i drive it.

 

If it was a fouled plug the bike would be a dog and barly run. My bike had the same problem. But once it got over about 4000 rpms it was great. I cleaned the carbs and adjusted my fuel/air screw. I think I went about 1 more turn out on them. The reason was because of the slip-on pipe. It made it run lean at idle. Now it runs great. Definitly dirty carbs or needs adjusting.

 

The carbs are under the gas tank I believe. Do I need to remove it to adjust the carbs? So one turn out should be counterclockwise right? I need to adjust each carb individually?

 

Correct, counter-clockwise.

There is a special tool that you can use to adjust the fuel screws without removing them, but if you don't have it you will need to remove them in order to adjust them. I would try half-turn increments to start. I would move all of the carbs the same amount.

You might pop the airbox open and see if there is a K & N Filter under there. When I put on just the slip-on the bike ran ok, but when I went to the K&N, it ran terribly. A factory pro race jetkit fixed things up nicely though.

You might need new needles (jetkit) to get this running right. If you are not comfortable tearing your carbs down, take it somewhere and have it done. I did my own, but it literally took 8 or 9 tries to get it right, and I had to tear the carbs apart each time to adjust a clip height or put in different needles etc.

 

Before you adjust the carbs you should really clean them first. You must take them off to do this. When I had me carbs off I used an electric ingraver to put a straight line on the fuel screws. I made it deep enough to get a small flat screw driver on them. I removed them and took a small hack saw blade and made the cuts a little deeper. So I would have no problem getting a screw driver on them. I installed everything and now I can adjust the fuel screws with just a small flat screwdriver. Saved from buying the tool. Then to tune it I left the tank off and used a small bottle with gas and hooked it to the fuel tube. I had to have the left engine hanger plate off and got my small hand in there to adjust them. It was a little difficult and hot on the hands. I would just buy the tool and save your hands from burns. But hey it worked!