Topic: CB550 Carb Float Height Question

[Duanob]

The plastic floats are so light that they do not depress the float needle when upside down.
If you do not believe that then do it yourself and you will know.

HAHA wrong! I have done it lots of times. you need to have the carbs tilted just right to have the tang just touching the float needle when measuring.

[jude0007]

I was able to set the float heights correctly.  I brought them into work and a gentleman helped me do this simple task.

I put the carbs back on the bike, hooked up fuel to test and bad news.  Fuel gushed out as quick as I could dump it in.  It was streaming out of all 4 overflow nipples AS WELL as the two vacuum tube/nipples.  The float needles appear to be in good shape.  What could my problem be?  I'm certain the float heights are dead on.

[ShovelHeadNed]

bump

[TwoTired]

The float and float valve work in conjunction the keep the fuel at a specific level withing the bowl.  If the carbs are overflowing, that mechanism isn't working as it should:
-The mechanism is maladjusted,
-the valve is not seating correctly (debris or deformity),
-the float is not pivoting smoothly/has impeded motion,
-the bowl's standpipe is broken or cracked,
-there is an alternate source of fuel inlet (such as a vent connection to fuel supply).

Scrutinize the items on this list, these answer lies in correcting one or more of these.

FYI: There are no vacuum tube nipples.  The early Keihin carbs used on the 550's only have Vent or pressure equalization nipples.  If fuel is coming out of those, then it is also filling the intake runners and cylinder, which pollutes the oil supply.  Check the oil level.  If too high or smells of gasoline, then drain it out and change it.


You don't think it wise to learn how the carb's internal devices are supposed to function when mending their aberrant behavior?  Have you read the Carb FAQ?