Topic: Intriguing shaped floatbowl CB500/550

[Deltarider]

Why does only one of my 4 floatbowls have that extra 'thing' (lip?) inside next to the brass overflowpipe? On my bike it's in #4 floatbowl (or should it be #3?) Was it needed in the manufacturing process or does it serve some goal unknown (to me)?
BTW note the 4 extra ... in the corners of the groove to keep the rubber seal in place. I don't have them on all my floatbowls so I'm curious to know from what model on they came standard.

[mrfish2]

That floatbowl looks exactly like the ones on my carbs, 087A's off of a 76 550K.

[Deltarider]

That floatbowl looks exactly like the ones on my carbs, 087A's off of a 76 550K.

How about that lip that sticks out from the bottom? Do all four of yours have that? I wonder why it is there.

[mrfish2]

Here's a pic from when i cleaned them



Your guess is as good as mine as to why that extra boss is there

[Deltarider]

If that boss is in all four, it maybe serves as a stop to prevent the floats going too low and the needle to get in a heeled position. Just a guess. On second thought... aren't the springleafs designed to do just that?

[754]

It's probably. There to keep the springleaf in line..

[Deltarider]

My carbset must have been altered by the first owner because only two of the four floatbowls have these 4 things in the groove (to have more grip on the seal), of these two bowls only one has this verticular tab. That got me curious and so I wondered what others have. I guess my carbset can't serve as reference. I'm pretty sure things have been changed by the first owner.