Topic: Float has gas in it

[70CB750]

One of the floats has gas in it, the plan is to get it out, find the hole and solder it shot;  does not seem like a big deal - is it?

The search here shows it was done before - just checking:)

[rklystron]

I attempted to do the same thing on one of my K0 floats. When I soldered it, it changed the weight of the float on that side. After many attempts I gave up when to a bone yard and found a replacement. You may have better luck that I did. I wou;d be very interested if you have success in your float repair. Best of luck.

[KingCustomCycles.com]

I have repaired floats that way and been successful.  It was common practice back in the day.

[ekpent]

Takes awhile sometimes to bleed the old gas out well.You may want to very, very slightly enlarge the hole when you find it,lay it so it is pointing downward and work it with a hair dryer,not a super hot heat gun a little. As it warms up pressure inside helps the gas bleed out better.  Inspect it well,I have had them fall apart in my hand before,sides seperate etc.  On the K1's at least the modern plastic will slip right in,not sure on the 4 cable K0 though if thats what you have.

[Duke McDukiedook]

Plastic float slips riiiiiiight in...

[BeSeeingYou]

Go light on the solder and it works fine.  IMO a temporary repair because if you have one leak others will follow just like in an old gas tank.  I have also found that those copper floats can develop hairline cracks that become too much to fix.  I have also removed the floats from the bracket , flipped them around and soldered them back on with the weak part on the top now.  That kept me riding for a few months till the season was over and I ordered new floats. My XS650's use the same copper floats.

[70CB750]

I did not expect replacement to be an option, does anybody sell new floats?

[Duke McDukiedook]

You can still buy them from a Honda OEM dealer but if I were you I would go plastic on that one unless you want to keep it 100% bone stock.
They have the KO carburetor listed in the parts fische so I would assume it is the metal float.

[Raul CB750K1]

I had a hard time with my CB350 carb setting until I heard sloshing in the float. My plan was exactly like yours. The float has a small hole, plugged with solder. So I put the tip of the iron in the solder, and suddenly I saw a tiny -and I mean thin- stream of gas pouring out from what seemed a peckle in the brass. It was a tiny, microscopic hole. Because of the heat, the gas boiled, the pressure rise and the gas went out.

Getting the gas out is no big deal. I am very experienced at soldering, but I couldn't make a decent job with the floats. The weight is definitely affected, and the more the float weights, it affects the float level.

The problem is that the brass sheet is so thin, that any impurity may cause a leak. I ended up biting the bullet and buying new floats from Honda, best $50 I have ever spent.

[Bodi]

If the hole is in otherwise sound metal it's no problem. If the float is corroded and paper thin you have trouble. Clean the area to shinyness with fine steel wool, use a dab of soldering paste if you have it.
To get the fuel out, the suggestions are good: warm it up and let the fuel dribble out. Heating it up for a while with a hair dryer or dipping it (hole up) in boiling hot water vaporizes any remaining fuel or water and when it cools you should have mostly clean air.
When soldering, you want to avoid heating up that air too much or the float will collapse from the pressure drop as the air cools. I wrap the float in a cool wet paper towel. A quick touch with a soldering iron and a dab of solder seals the hole. If you heat it up too much the solder stays soft long enough for the expanding or contracting air inside to blow or suck the hole open again. I don't think the slight change in float weight will affect the float level enough to matter.

[dshot59]

I repaired the float in my old Honda three wheeler with stuff called Seal-all. It`s avalible at auto parts stores and made for gas tank leaks comes in a yelow tube the stuff is great. You can apply it to a gas tank while the gas is leaking out and it will stop the leak.I smeared some on let it dry then hit it with some steel wool to clean off excess. Been in there for a few years now and no problems still runs great.

[ekpent]

I repaired the float in my old Honda three wheeler with stuff called Seal-all. It`s avalible at auto parts stores and made for gas tank leaks comes in a yelow tube the stuff is great. You can apply it to a gas tank while the gas is leaking out and it will stop the leak.I smeared some on let it dry then hit it with some steel wool to clean off excess. Been in there for a few years now and no problems still runs great.

  I will say that Seal-All is some good Sh#t. I repaired a crack in a carb body where the emulsion tube screws in and it lasted as long as I had the bike.

[70CB750]

I found the hole yesterday,  the trick was to hold it in hot water.  Drilled a tiny hole, shaked the gas out, sanded, prepped and soldered.  It seems to be holding.  And here are weights of floats, just for kicks:

       [grains]
1. - 165.1
2. - 157.6
3. - 161.1
4. - 162.5


You can tell which one is soldered now (#1) , but the differences between 2 and 4 are significant too.  These numbers averaged from 3 values and I trust my reloading scale with my life - i.e. numbers are within a fraction of a grain.

I will see how it works and  may get new floats if necessary.  Thank you , guys. 

[rklystron]

Nice work! I am very interested on how well it holds up. Nice to know the weights as well as you say, "Just for kicks."