Topic: Floats at stock height, overflowing?

[Dimitri13]

I set my floats to stock height, and now they're overflowing through the overflow tube. Do floats break down over time and cause this?

'74 CB550 K0

[INSANE REINDEER]

I had mine do this for a while and sometimes I had to actually tap the bowls with something when refilling them from dry. I guess they just slide to one side and got stuck for me. If you're sure they set to spec then try that. Sometimes shaking the bike back and forth helped a little.

[mrbreeze]

They are sticking or the needle & seat are bad (or piece of crap holding the needle open)............gotta be a detective now...............you'll get it!!!

[dave500]

do you have pd carbs?the over flow brass tube in the bowl may have a split.

[TwoTired]

I set my floats to stock height,

What do you think stock height is?

and now they're overflowing through the overflow tube. Do floats break down over time and cause this?

'74 CB550 K0

Did you look at the bowl stand pipes carefully for cracks?

Did you mix up the valves and seats from married pairs?

Did you put the floats in upside down?

Didi you use new bowl gaskets?  Are you sure the gaskets didn't poke inward to interfere with float operation?

[Dimitri13]

Reindeer: Didn't work.

Breeze: Rebuilt carbs, so brand new needles and jets.

Dave: Not sure what PD carbs are, but the overflow pipes seem okay.

TT: Whatever the manual said; 22 or 23mm (can't remember).
Didn't mix up any parts. Only took them apart one at a time.
Pretty sure the floats are in right-side-up (put them back in the same way they came out, and it looks like it does in the picture of the manual).
There's no float bowl gaskets on it right now (waiting for new set).

I also should've been a bit clearer and stated that the gas will flow out of the overflow tubes at about the same rate as it does from the gas tank.

Does anyone have a picture of what stock height looks like, by any chance? I'm at 22 or 23mm, but it seems pretty close to the roof of the float chamber.

[tango911]

it depends what your measuring from,  stock is 22mm,  and that is also with the float barely resting against the needle just before it compresses the little spring. measuring from the top of the float to the base of the carb where the gasket sets.  hope that makes sense, if not TT will splain it better.

[MCRider]

"Breeze: Rebuilt carbs, so brand new needles and jets."

"Needles and jets", are not "float valves".  Just checking.

[Really?]

Dirty fuel, dirty tank, bad filter, fuel line coming apart from the inside due to age?  All of those contributed to my issues including having to replace the needle and seats.  The teeny tiny garbage coming through would get stuck at the top of the seats and hold the needles open.

[CoachDoc]

I had the same problem- I pulled the float needlws and seats and cleaned them carefully, going over the needle tips lightly with emery. No problem since.
 That said I agree with others that you could also have leaking overflow tubes or the floats themselves may be leaking.

[Dimitri13]

Just put in new fuel lines. The float needle and seat are brand new too.

I'd also like to add that I had the floats at.. something like 40mm (how it was when I got it), and it didn't leak fuel, so I don't think it's the float needle (but it was too low and I wasn't getting enough fuel, so I changed it to stock height. I'll probably try something in between, but closer to 22mm).

Next step will probably be replacing the filter and de-rusting+coating the tank, anyway.

[Magpie]

Are they Honda needles and seats or aftermarket? I replaced my seats with aftermarket and they all leaked. Reinstalled the ones I took out and they worked fine. A good way to clean the bottom of the seat is to sharpen a small dowell or chop stick with a pencil sharpener and rotate the sharp end in the hole in the seat for the needle, you can use some carb cleaner on it if you like. the wood is abrasive enough to clean it without damaging it. The Honda mecanics here will not use aftermarket carb kits because of too many problems coming back to them.
Hope this helps,
Cliff.

[seanbarney41]

how about popping one of them float bowls off(not sure on a 550, but you can often get in there with a shorty screwdriver without removing your carb rack from the bike), snapping some pics, and posting them...