Topic: float bowl issues

[tonian]

Recently, I bought a '78 550k. Its spent the last 18yrs in a barn, gumming up. The carbs were completely stuck... but I tore them down, cleaned them up, and slapped them back together. Actually, seeing as it was my first rebuild things were very slow going. At my first attempt to start it up, I realized the float bowls were dry. I made sure passages were clear then adjusted the tangs, tested them, and tried starting it again. No dice. However this time, when I unscrewed the float drain plug, gas came from the overflow outlet, not the drain plug. Can anyone explain this? Also, anyone have suggestions on what will get my bike running... Do float level have to be precise for it to even fire?

[jdpas29]

hey... i think i understand your question.  you don't have to back the screw out all the way to drain the float bowl if your carbs are like my 78 750K.  you just turn it a turn out or so and the gas will come out of the overflow tubes. 

the fuel doesn't have to be exact for the engine to fire, but to get it to idle right it will have to be close.

make sure the floats can swing freely on the pins that they swivel on.  steel wool 0000 works great for smoothing up the pins.  you may need new float needles as well if it's been sitting up that long.

did you get a new battery?  points?  plugs?  does your ignition turn over at all?  what does it sound like?

[tonian]

so JD, maybe this is a stupid question but..  fuel is designed to flow out the overflow and not the screw hole on the bottom of the bowl when unscrewed?

 it's got a new batt, new plugs, didn't do the points, but there is a strong spark. ignition turns over very well.

[m00ntan]

It's something seriously wrong in the assembly.  You have fuel into the bowl, and no air.  It's pressurized from the petcock.  When you let the pressure out with the drain plug, it flows out the overflow.  I think you have a do over.  Try a new float valve and seat.

[Bodi]

Some carbs have this design where the drain screw opens a passage to the overflow tube.

[jdpas29]

so JD, maybe this is a stupid question but..  fuel is designed to flow out the overflow and not the screw hole on the bottom of the bowl when unscrewed?

 it's got a new batt, new plugs, didn't do the points, but there is a strong spark. ignition turns over very well.

yes... if they're like mine.  that's what is happening.

after each carb bowl has had time to fill, shut off the petcock and drain the bowls individually into something you can measure.  make sure they're all close to the same.  if you're getting fire and you're getting gas... chances are you're getting air.  is the airbox on or removed right now?

i know this sounds silly but make sure the kill switch up on the handle bars is in the right position.  8D

[tonian]

Airbox is on. I cleaned the mouse nest out of it, placed a new filter in. It should be good.
I haven't had a running motorcycle for the past two years, I feel this season slipping by way too quickly. It's a really horrible feeling.
I'll try out everyone's suggestions, thank you, and if anything else comes to mind, let me know. I'll give an update as soon as I can look at it again.

[m00ntan]

It seems to me, if your float valve and seat is new, and your jets are't plugged, and the air tube isn't plugged, but gas runs out he tube only when the drain plug lets air in, I shouldn't be able to hold a glass of water upside down.

You did put filters on that fuel line?

But I don know anything, check with Dan:
 http://www.dansmc.com/carbs.htm
Or try the old man:
 http://oldmanhonda.com/MC/Rcarbs.html

[tonian]

well, it's running. not on all four, but at least it IS running. I have to keep it choked and the throttle open, otherwise it dies quick. theres gonna be a lot of troubleshooting ahead so wish me luck. and thanks again for everyone's advice.