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[timktm]

On the knowledge of you guys I have decided to go ahead and take the carbs back off. I am going to try and repair the concave ones. Any suggestions? I was thinking about using solder as a dent puller. Or sweat them apart and make it convex and resolder. Then use a scale to weigh them?
Thoughts?
Tim

[TopCatGr58]

Others are much smarter than I with regards to scientific knowledge, such as Boyle's law, atmospheric pressures, changes with temperature, etc.. I know that the floats were made at normal atmospheric pressure ie. 14.7 lbs/sq. in..
A compressor can create many more atmospheres of pressure within the float bowls, and so it was relatively easy to squish them concave.

The problem is getting enough pressure INSIDE the floats to push the metal back out to the convex shape. Putting the floats into BOILING water would increase the pressure, but I don't know by how much since it would only bring the air inside up to 212 degrees F. Using a heat gun could allow a bit higher temperature and therefor more pressure, but can't recall at what temperature the solder use to build them will melt...~400-500 or so?? Putting the float in a vacuum chamber would also only generate 1 additional atmosphere of pressure.

SO...using a shop vac with a hose/adapter fitting that would be about the size/diameter of the float might be able to apply more pull against the side of the float??

So...you can see why folks have usually opted to replace them vs. trying to fix them! And, I'm pretty sure I've heard of several folks that have put in the newer 80-81 style plastic floats into the older style carbs, and were successful. You will probably need to use the clear tube external fluid level check to set the floats more accurately than just relying on a physical mm. setting internally. Perhaps some of the folks who have done the new floats in old carbs mod will post about it.

T.C.

[MaximPhil]

I would like to hear if the BOILNG Water idea works.
No down side if you are going to replace them anyway the heat gun or vacuum cleaner hose suggestion is high risk in my opinion.
Phil

[Schming]

On the knowledge of you guys I have decided to go ahead and take the carbs back off. I am going to try and repair the concave ones. Any suggestions? I was thinking about using solder as a dent puller. Or sweat them apart and make it convex and resolder. Then use a scale to weigh them?
Thoughts?
Tim

Before you go thru all that trouble, let me check my stash, I seem to remember I have some early XS 750 carb parts and this link says they'll work:

http://xs1100.com/partinfo.php?myid=...A2-14985-01-00

I'll get back to ya tomorrow.

[timktm]

Great info by everyone and shming, thanks that would be cool. I will do some experimenting, as I enjoy it anyway. And on the float testing using the tank and fluid hose looks interesting as well. I will be reading up on that too.
Tim

[timktm]

Well, got em fixed! Un soldered the hole and applied air and "pop", the dent came right out. Now testing for leaks and will check for equal weights later today.
Tim

[Schming]

If you find you need 'em I have three:

[TopCatGr58]

Hey Tim,

Glad to hear you found a way to fix them. I was thinking about this thread when I was watching this weeks MythBuster's episode I had DVR'd.

Whodda thunk you could squish a RailRoad tanker car with just almost absolute vacuum inside and 1 normal atmosphere outside. The tanker was made with 1/2" thick steel, and in a perfect circle/cylinder with convex shaped ends, and so it actually didn't collapse the first 2 times they tried. Only after they put a bit of a dent in the cylinder did it compromise the strength of the cylinder shape, and that allowed it to totally collapse the tanker sides!

T.C.

[Radioguylogs]

I saw the same episode of Myth Busters- it was quite dramatic.

For the record, I have used a heat gun at least two time I can remember to successfully pop out floats that were caved in. I felt I had nothing to lose.

[timktm]

Just love how science can relate to our hobbies.
I did the wet set float adjustment method and got all four to the level like in the description on this forum. I see why that method is much more accurate than just measuring the floats. Especially when repairs have been made and potentially changing their weights. Waiting on parts now......
Tim

[motoman]

Just love how science can relate to our hobbies.
I did the wet set float adjustment method and got all four to the level like in the description on this forum. I see why that method is much more accurate than just measuring the floats. Especially when repairs have been made and potentially changing their weights. Waiting on parts now......
Tim

Good option for the float fix. Many yrs. back here on the site, your trick was used with success akso, Also, know its a bit more involved, but your fuel level concern was an excellent option to check. I know it makes one REALLY good and QUICK at carb R/R in order to re-tweak the floats abit, but WAY worth it for engine smoothness at ALL and any rpm. Get ALL cyls. doing the same amount of 'work' at a given rpm IS VERY important!

[timktm]

Man what a bummer, ordered the wrong part yet again!!!! I am looking for the rubber washer that has the five holes in it that goes in the petcock. Ordered the wrong one from boats.net. They don't have it listed individually on the schematic so I picked the wrong one. Can someone please help me order the correct one. I ordered from the 1980 sg so that was the correct petcock.
Tim

[bikerphil]

These are correct for your 79 Special.....

http://www.georgefixs.com/xj1100-xs1...00sf-xs1100lg/

[timktm]

I'm looking for the part number for the individual seal.
Tim

[bikerphil]

Yamaha P/N 3H3-24523-00-00

https://www.shopyamaha.com/parts-cat...EL_COCK_PIPING