Hey . . i got a 98 cbr F3 . . .the bike runs great throttle response is good but the damn thing idles so freeking high . .i checked the thriottle stop its backed all the way off and the main idle set screw is backed all the way off the cables have slack in them so they arent pulling the valves open and giving it more fuel . .whatcould possibly be the probleme? im wondering if some of my hose routing has something to do with it you can check it out on my previous post Need Help with hose Routing . . Everything Apears to be correct except im missing the 2 hoses that T off in the headlight area but it seems like they kind of hang their anyway and just chill so it shouldnt make a difference with just one hose hangin there right? Also if i apply vaccum to that upper hose the idle calms down . . .i need help with this one bad. any help would be greatly apreciated. . . . .maybe i should stick to car mechanics this a whole new ball game for me lol

 

Sounds like it has something to do with those hoses in the headlight, as you say applying a vacuum to the top one brings the tick over speed down. I'd pop down to your local dealer and try to get a mechanic to give you free advice on how those hoses should be connected. Otherwise borrow a Haynes manual to see how they are routed and connected. I'm sure the answer will be a simple one! Good luck!

 

I had that problem, but it was my throttle cables. I could twist the throttle backwards and the idle would go down, so I ended up adjusting the throttle cables. That doesn't sound ilke the problem you have but it could be.

 

Remove the air filter, and with the engine off, lift the black slides that are down in the throat of the carburetors. Use a flashlight to look at the butterfly. It's the shiny brass looking plate that opens and closes with your throttle. Make sure that each of them look exactly the same. When you're not twisting the throttle, those plates should be essentially be closed, or maybe a hair (and you know what kind of hair I'm talking about) open. If they look different from each other, or are open any amount, then it's probably a mechanical issue with your idle adjustment and or some really bad carburetor synchronization.

Let us know what you find. Also, check StepheeGee.com for an F3 manual you can download. It has the hose diagrams. Is your bike a CA model or 49 state version ?

 

Not a california model thank god . . i make sure when i buy anything vehicle wise that it is non california because it is an unecessary pain . .yea ive looked at the butterfly flaps they seem ok so what i did was i brought my car knowledge into play and said F*&$ it and removed the gas tank and used a can of gum gutter and just sprayed in their while i held it WTFO and after doing so i noticed the diaphragms moving up and down now where as before they didnt so i backed off and sprayed it into the jets that are visible and just started filling up the filter b4 the fuel pump and letting it siphon from that and it seems to have cleared it up . . but now the bike has been sitting for a day or so now so we shall see if that has 100 percently fixed the probleme