My 96 CBR1000F is running rich. Changed the oil, air filter, oil filter, and plugs. I noticed the half inch breather tube that connects between carbs 1&2 and 3&4 and goes forward to the evaporative emissions carb air vent control valve was disconnected @ 1&2 and 3&4. Thinking I must have knocked them off when I pulled the plug wires I reconnected them and she wouldn't start, so I disconnected them and she runs as before.The two shops that I took her to say its my floats. One shop wants $375.00 plus parts, the other $315.00. Niether is saying what this carb work intails. Im getting 20 mpg around town and she runs real smooth @ higher rpm. Can I get some advice before the mechanics replace the P32 space modulator, and the flux capassitor?

 

Are the damn enrichners at full in when you turn the choke off?

I hate to see you blow hard earned cash on something easy to check.
Lift the tank and see if they are going all the way in.

There is a slide that moves left to right with choke on. It should travel right to left and the pins that it pulls on should be in with choke off.
Also the very first thing a shop will check is the air filter. Sometimes a mouse likes to build a home in the air box. I have seen this many times.

Floats don't just go out of whack unless someone has played with them.

I worked in a shop and we sent a new bikes out. When we got a call on it we had them return the bike back to the shop. Most times it barley run and was running rich. The first thing I would check had a 100% fix rate was that the owner had taken the stupid plastic shipping cover off the seat and stuff it under the seat where the intake would suck it in.

 

Hey:

I 2nd TBT, as that happens a lot also have seen spare rubber/rain gloves stored under the seat or ziplock bags do the same thing.

Dub

 

Air box is clear, put on a new air filter day before, no gloves or bags, I'm going to check the enrichers right now. Thanks for your help guys, hope it works.

 

Choke and pin are fuctioning correctly.

 

Hey:

Well a set of used carbs on CL or Ebay is around 125-200 $USD, so I would go that route before having a shop change out the floats for 300+. You could always relist them after you get your problems sorted. Also what main jets are in your carbs, is the bike stock? Pipe K&N? could have been over jetted by previous owner/ how long have you owned it? this will help to troubleshoot better. how long has this been going on? Is this a Cali model(GAS&Perf PIG)?

Dub

 

Hey:

Just read your inro and 20MPG city is not all that bad if your at more than sea level, on the throttle @6,000 RPMs or better and it is hot and humid with a high DA. Was your valves checked for adjustment as that and carbs out of sync can contribute to excessive fuel consumption.

Dub

 

I don't play with my throttle in the city traffic - bike still gives me better than 35+ MPG. over 40 on open road at high speed.......

Something else is wrong - some carbs you can adjust the levels on floats, some you can't. I'd say there's a problem in another area, like TBT said - jet sizes, etc etc.
Maybe some seafoam through the carbs and see if it improves.........
and check the choke lever and cable, as said above........

 

Hey:

He is in the States so thats Yankee gallons not the Queens, so in the 20s that may not be far off, if he has a bigger rear sprocket and high DA. I agree something else could be wrong but he needs to give us some more info, to see if it is. I often get 25-30MPG in the city during the summer and have gotten as low as 19 MPG before city, (altitude, 6400 DA, 100+ temp,{40C}, 48t rear sprocket, agressive riding style, lots of RPMs,39mm FCRs, 155 mains, big OMT cams, big bore kit, bigger stroke FKE crank) and I can assure you my bike is in tune and running very well, Thank You. But it is far from stock, so we need to find just a little more out to see what if anything is wrong or not.

Dub

 

jcstumpy1,
You being in HI and what you describe would have me thinking that you have a CA model. That air recirculation system sucks. There are threads and members that can help to remove that crap from the bike. Don't let the mechanics replace the P32 space modulator, and the flux capacitor. They may mess up the inverse reactive current of the unilateral phase detractors that sync the cardinal gram meters. With the CA emissions cob job on the bike the parametric fan hook to the hydrocoptic marsal vanes could be causing side fumble in the ambiphasient lunar wing shaft.

In other words, the CA pluming should be removed or you are just throwing darts.