1979 xs1100s ignition issue

[motoman]

I did take those off and cleaned. Ha! I cleaned them till 10 at night. I went a little ocd.

No such thing as ocd when it comes to carb cleanliness...

[dondons1984]

Lol. I feel like I got ocd when I was cleaning them. I had a pick set can of air and carb cleaner on a table and man I was being a clean little bastard. I even thought about polishing them. Got most of them back together except for one carb. Got to get the float for it. Have a small pinhole in it. I then just need to figure out what am I suppose to space my carb floats to? Bought the tool for it recommended by Greg cause mine is a little missing tool. I swear I'm going to get a motorcycle tool box only.

[motoman]

Lol. I feel like I got ocd when I was cleaning them. I had a pick set can of air and carb cleaner on a table and man I was being a clean little bastard. I even thought about polishing them. Got most of them back together except for one carb. Got to get the float for it. Have a small pinhole in it. I then just need to figure out what am I suppose to space my carb floats to? Bought the tool for it recommended by Greg cause mine is a little missing tool. I swear I'm going to get a motorcycle tool box only.

Carbs upsidedown with floats installed, measure from carb recess where gasket would normally set(gasket removed) to highest point of float, setting ALL eight EXACTLY the same to the millimeters specified for that particular year carbs. No worries, Greg will get cha' squared away with the carbs.

[dondons1984]

Lol yeah Greg knows what he is doing. I am researching what to set them at and then will get that done.

[DGXSER]

25.7 mm from the gasket surface for the earlier style carbs. And be sure to bench test them for leaking float valves before you go throwing them back on. Also remember to bench synch them before you throw them back on.

[dondons1984]

How in the world do you bench test carbs?

[dondons1984]

Ok so I just bench synched the carbs so that was fun. I looked up how to bench test them and did it that way. no leaks at all. so all good so far. just dont freaking jinx me!!!!!! Only carb i cant test is the one I need a float for. wondering if I can take the one off my cb750? hmmm now that is an idea. anyone got any input on that part?

[3Phase]

Don,

CB750 floats? I like it! I'd buy another float or fix the leak but it's your bike!

Where is the leak?
Is it in the solder seam holding the two halves of the float together? (most likely)
At the float/float arm solder junction? (someone bent/twisted/abused the float)
Somewhere else? (not as likely but it happens)

The explanation of how to repair the float looks more difficult than it really is but the leaks can be fixed if you have a soldering iron and some time. If you don't have the time just buy another float that doesn't leak and don't worry about it or try to fit your CB750 floats. If you don't have a soldering iron you could buy one (or two, or three) for what a new float would cost.

Moving right along! To fix the float, put it in hot water and mark the leak(s) with a metal scribe.

De-solder and open the vent hole in the side of the float so the float can be heated but won't collapse when it cools off. The vent hole is underneath the single patch of solder in the center of the outside of each float.

Drain any water or fuel out of the float and make sure it's dry inside before you start or the fuel/water will boil out of the float and contaminate the solder as you try to make the repair.

Clean! the outside of the float to get rid of any fuel residue, finger oils, and oxidation.

Fix the leak.

Quickly solder the vent hole closed. If the float gets to hot while you close the vent hole it'll collapse as it cools.

Check for leaks again by putting the float in hot water.

Put the carbs back together and go ride!



Be careful:

Don't overheat the float when you're trying to fix it or it'll come apart and you'll have a lot of fun trying to put it back together again.

Don't add too much solder or it'll change the weight of the float. The float will still work but you won't be able to use the normal factory float height setting and the float height will have to be set by checking the the dynamic fuel level in the float bowl with the engine running.

[dondons1984]

just waiting on parts now.

[BA80]

Here's 2 NOS floats.

http://www.ebay.com/itm/YAMAHA-XS400...7d2005&vxp=mtr

[dondons1984]

damn that made my nuts hurt!!!!

[dondons1984]

greg got the parts you sent me. How long should I let them sit in gas? If I dont will I leak?

[BA80]

Overnight should be good. They haven't been in contact with it for a while and are kinda dried out and hardened.

Hope they work for you man.

[dondons1984]

thanks. I didnt have to go in till 2am (working the farm for 12 hours) so I soaked them in to see if they would right off the bat kind of work and I was leaking gas (yes I read your note I am just impatient). so now I will let them soak in gas overnight and hope that they work. they looked in pretty good condition to me.

THANKS A TON GREG!!!!!

[BA80]

Sometimes they will leak for a bit if the parts are old but after a bit of use it will stop. Be sure you have the good side out against the lever.