Honda Twins banner
1 - 15 of 15 Posts

·
Premium Member
Joined
·
667 Posts
Discussion Starter · #1 ·
Has anybody on the forum repaired a leaking float? The one I am thinking about trying to fix is out of the 70 CL450 scrambler. I had another one to put in my bike but thought I would try sealing this one up since they arent available anymore from Honda ( I think ).
I know it could probably be soldered but I was wondering about some kind of glue or paint that it could be dipped in to seal it.
Don
 

·
Sensei
Joined
·
27,180 Posts
You should use metal mender solder (acid flux) not electrical solder (rosin flux)..Plus, the tin to lead proportions are different.........
 

·
Registered
Joined
·
3,926 Posts
I just use a very thin solder from Radioshack on my floats. A little clear plastic tube of coiled solid solder wire. I apply paste flux from a tin to the cracked area, and then use the little tube of electronic solder from Radioshack. It's always worked well for me..


GB :mrgreen:
 

·
Premium Member
Joined
·
667 Posts
Discussion Starter · #6 ·
Thanks guys, I had a float in my stash of parts so I am back on the road again I just hate throwing this away. The reason I had extras was because when I was getting my CB450 running I had the same issue and was told the new floats were not available so I thought it was worth repairing for future use. I am going to try the soldering. I did one years ago but I may have had the wrong solder, heat, or something. I wasn't succesful that time.
Don
 

·
Registered
Joined
·
84 Posts
I tried soldering one of my original floats without much luck. I did find and purchase new OEM floats from MotorCycle Solutions LLC for about $20.00 each, IIRC. I only needed one, but purchased two so I would have a spare as I think their stock may change from time to time.
 

·
Registered
Joined
·
3,537 Posts
The trick to a good solder joint is cleanliness, correct solder, flux and the right amount of heat. Too much heat will make the float fall apart. Not enough will prevent the solder from drawing (capillary action) into the joint. A soldering pencil (iron) in the 35 watt range will not provide enough heat to the melt the existing solder. A good solder gun will be between 100 and 250 watts. I like to use a small hobby butane torch. Here is my recommendations for success:

1. Clean the affected area with a clean stainless steel wire brush. The metal should be bright and shiny.
2. Apply flux to the area to be soldered. The flux is to prevent the solder area from oxidizing from heat.
3. If you are using a soldering gun (a soldering pencil will not work), clean the tip and apply flux.
4. Heat the area to be soldered. Apply the heat on the side away from other joints you do not want to de-solder. If you are using a gun, melt a small amount of solder between the gun tip and part being heated. This will facilitate heat transfer.
5. If you are using a torch, the tip of the blue flame is the hottest. Be careful since the flame will spread and areas of the part may get too hot. This is a feel you will need to develop.
6. Monitor the temperature of the part by brushing the solder against the metal. If you are doing it correctly capillary action should draw the molten solder into the joint. Don't try to force the solder into a cool joint, a cold joint will occur. Don't allow the metal to become too hot, other joints my melt.
7. Do not allow the part to move until the solder has solidified. If you move it too soon, a cold joint occurs.
 

·
Premium Member
Joined
·
667 Posts
Discussion Starter · #9 ·
Thanks for the tips. I think I am going to try fixing this one just to do it. I think I have everything except the flux. I need to get that first. I dont think my gun is 250 amp though, I think it is 125.
Don
 

·
Registered
Joined
·
3,926 Posts
This is the stuff I've used with excellent results. Whether people here agree or not. It's not rosin core and the paste flux is not an acid flux to my knowledge...? Your results may vary but I haven't had that repaired float on my buddies CB100 fail yet, and we BEAT on that bike! I also repaired one on my old CB125 and it was perfect the entire time I owned it.



The thinner the solder the quicker and easier it melts. That seemed to help me avoid accidentally de-soldering the entire float joint. I used an el-cheapo "pencil torch" and it worked great.
http://www.radioshack.com/product/index ... Id=2062722


GB :mrgreen:
 

·
Registered
Joined
·
363 Posts
that is acid flux GB, any plumbing or radiator flux is acid, regardless of its water soluble or whatever else it says on the tin.. electronics flux is rosin, smells like a pine tree when you use it.. be sure you never use acid flux on wires, it will corrode and cause the joint to fail. modern plumbing solder is a real bummer, its all tin, no lead, a nice 60/40 pb/sn is what you want with a good acid flux.
 

·
Registered
Joined
·
91 Posts
Hi Don

I have done this many times. The trick beside getting the area clean (I use fine sandpaper), if you are using a soldering gun is to heat the gun to smoking hot. Tin the tip of the gun and after fluxing the area to be soldered, put the solder directly on the hole or crack and hit it with the gun . as the brass is so thin, the solder will melt quickly. Just a quick touch and get the heat off of the float to prevent desoldering the seam or mount. You want just a coating, not big blobs as it will add weight. You can hit it again with the gun and wipe excess off.
Terry
 

·
Premium Member
Joined
·
667 Posts
Discussion Starter · #13 ·
Thanks everyone. I have a couple now that need repaired so I am going to keep them and give it a try. Since I dont really need one right now I may make it a science project for a cold winter night in the garage.
I would rather ride every chance I get right now.
Don
 

·
Registered
Joined
·
101 Posts
If you are using a soldering gun, you're gonna want to be careful of not over heating the solder and brass. Head to the local hardware or hobby store and grab a piece of brass sheet to practice on. .010" to .015" thick should be OK. And a fine stainless steel brush. Learn how to keep the soldering gun at the right temp by pulling the trigger occasionally. You will see the solder get shiny and start to flow. Try not to add much heat beyond this.
Look at the inside surface of the floats. You will see a little dot of solder. This is the air vent hole. First and last to be soldered.
Have a container of hot water ready. Not boiling hot, but not hot tap water. Wire brush the float and dip it in the water. Tiny bubbles will reveal the leak. Pull it out and dry it. Tin up the iron and apply some flux to the vent hole. Now hold the float so the vent hole is facing down. When the solder is melted, you don't want it to drop into the float. Adds weight, it tinkles and you'll never get it out.
Open the vent hole, then move on to the fix. You may find that while applying new solder, some black crusty junk may appear. Guess it sorta depends on the flux you use. Anyway, whenever the crust shows up, brush it outta there. You want solder and brass, that's it. Keep an eye on the junction between solder and brass. The transition should be smooth and flowing. No lumps or appearance of beading up. That means there's still impurities coming off of the brass or from the interior of the float through the crack.
Try to add the least amount of solder as possible. A heavier float effectively raises the fuel level in the float bowl.
After you think you've got it fixed, close up the vent hole and dunk it hot water again. Tiny bubbles....do it again. And again. :cry:

NE
 

·
Premium Member
Joined
·
667 Posts
Discussion Starter · #15 ·
I am definitely going to have to pick a day that I am calm. Sounds like an operation that I am usually not good at. I am more of a big hammer kind of guy. :lol:
I havent been having much luck with soldering even wires lately but I haven been using flux so that might be my problem. I think I am going to stock up on soldering stuff and make sure I have the right material for that time that I can try this.
Thanks for all the help.
don
 
1 - 15 of 15 Posts
Top