Question

What is the concensus of doing a solder repair on a brass float? I would attempt it after making sure all fuel has been removed - maybe leave it a couple of days on the hotwater cylinder. Then the soldering has to be done super quick so the air inside does not expand too much - I would probably hold the float in ice cold water while soldering to minimise this.

Has anyone tried using a spot of JB Weld? It is supposed to be petrol resistant so a mega small spot may work?
 
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In my opinion it's a fools game to attempt solder or other kludge fixes to something as critical to the core of your motorcycle as the carb float. They are brass, expand contract with thermal cycles, and develop stress cracks all the way around the perimeter.
Yes I have done it and regretted trying. If you look you will find a soldered shut pin hole in the center of each float they solder the edge then quickly seal that hole after it's cool.
 
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What is the concensus of doing a solder repair on a brass float? I would attempt it after making sure all fuel has been removed - maybe leave it a couple of days on the hotwater cylinder. Then the soldering has to be done super quick so the air inside does not expand too much - I would probably hold the float in ice cold water while soldering to minimise this.

Has anyone tried using a spot of JB Weld? It is supposed to be petrol resistant so a mega small spot may work?
The job weld thing has been suggested a few Times think I'll take them off and try it
 
Best source for BS38 floats is 3M at 650Central (original Mikuni, best price). Best source for float needle and seat assemblies is right from Yamaha. Aftermarket ones are hit and miss, many times leaking right out of the box.
So the carbs I have are mikuni bs38 ? Just wanna make sure I get the floats and kits I need ....but it did almost run guys !!!!! Almost 45 sec. Or so ...the exhaust sounds way meaner than I thought it would
 
Yes BS38, same float used from 1970-79
While you have them apart check your jet sizes and that they are genuine mikuni. It's real common for guys to buy rebuild kits. While chinese brass is often a bad idea, the XS650 used different size jets nearly every year, most kits NORMALLY have the wrong jet sizes in them. It might be a good idea to post up pics of your carbs and report the jets you find, lots of carb swapping is done, you might have carbs from a different year....
650carbspecsreducedsizeey7.png

mikunipilotjetsmoddedam2.gif
 
Yes BS38, same float used from 1970-79
While you have them apart check your jet sizes and that they are genuine mikuni. It's real common for guys to buy rebuild kits. While chinese brass is often a bad idea, the XS650 used different size jets nearly every year, most kits NORMALLY have the wrong jet sizes in them. It might be a good idea to post up pics of your carbs and report the jets you find, lots of carb swapping is done, you might have carbs from a different year....
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