puking carb

[eroellig]

So, finishing the carb bench adjustment should be the last big thing I need to do before I can roll outside and try to start. I used the grease zerk idea to attach clear tubing to the float bowls so I could see how even I got the gas levels.

I hooked up the gas while the carbs were upside down with the bowls removed and the valves seemed to be holding the gas back. I blipped the floats & got gas to the valves and everything seemed to stay put. However, once I put the bowls on & turn the carbs upright, it wasn't as pretty.

The gas level in bowls 1, 2 & 3 all seemed to fill up to about the same level (not positive since I didn't have long to look.) Then carb # 4 started puking gas. I've drained the gas back out of the carbs, but #4 appears to be able to move the float without any problems. Even if I try shoving the float to one side or the other on its pin that it hangs on. The valves are all new. # 2 carb also has a new float.

So, what do I look for?

I did not "dip" the carb bodies, but I've run 2 cans of carb cleaner through them, soaked them with carb cleaner and blown compressed air through every oriface. Every jet & adjustment screw was removed to allow cleaning. (bowls, jets & such were dipped).

I did notice what looked like a little flushed out crud in the clear tubing for #1 carb. Perhaps I just need to look and see if there is anything like that plugging #4's valve tip...

I will note that before I tore 'er down, at least one of the carbs (don't know which one) was also puking now & then, so I have no idea if it is the same one or not.

So, suggestions?

Eric

[DiverRay]

Eric, I vote for junk keeping the float open. Try flushing fuel through, or you may need to take the carbs off so you can pull the seat and needle on the bad carb. You DID put on inline filters???

[TopCatGr58]

Re: puking carb

Originally posted by eroellig
The valves are all new. # 2 carb also has a new float.

So, what do I look for?
Eric

Hey Eric,

You say the valves are new, but did you remove the valve seats and replace the O-rings that are around the bottom of the valve seats? They can harden and leak just like a stuck float valve?

Otherwise, what Ray said, crud sticking the valve open! Flush and use inline filters, and put new fuel lines on. You can try draining the tank some from the RESERVE setting on the petcock and do it thru a coffee filter to look for crud, if so....then you'll know where it's coming from!
T.C.

[eroellig]

Originally posted by DiverRay
Eric, I vote for junk keeping the float open. Try flushing fuel through, or you may need to take the carbs off so you can pull the seat and needle on the bad carb. You DID put on inline filters???

I don't have to take the carbs off...they are still on the bench. I have the filters. I'll go down in a bit & pull the parts & give it a looking over. I think I'll also double check to see if I can see any cracks or holes in the float (plastic).

I'm wondering if, when you bend the tang on the float to adjust the height, it fhere is a shape you need to try for. In other words, is it possible to bend the tang in such a way that it "catches" on the valve & doesn't close with the light pressure of rising fuel?

Eric

[TopCatGr58]

Originally posted by eroellig

I'm wondering if, when you bend the tang on the float to adjust the height, it fhere is a shape you need to try for. In other words, is it possible to bend the tang in such a way that it "catches" on the valve & doesn't close with the light pressure of rising fuel?

Eric

Eric,

A fellow Xsive posted a short while back about the tang being bent so that the needle valve slides too far out of the valve seat and gets stuck slightly tilted/cocked and prevents it from sliding back up when put back right side up. He posted photos as well, but I don't know the link to it right now, but you could probably find it with a search!
T.C.

[eroellig]

Tang observation & a measure of success.

TC, All,

So, I took it apart and decided that I'm an idiot. and don't know how to clean a carb There were TWO big bits of crud under the valve tip. Cool. Easy Fix.

Gas it up again and. %@#$^, it puked again. Ok, I figure it must have flushed another bit of crud into the valve. But, NO!!! This time its clean.

WTF?

So, I took a good look at the tang under my magnifying light. I saw what looked like a wear spot. Probing with a pick revealed that I could JUST feel it. So now I'm wondering if there is a "hole" worn in this tang causing it to grip the top of the valve and jamming it. I took some 1500 grit sandpaper and worked on the tang for a while to polish it. Next try IT DIDN'T PUKE!. But now I wonder if this is a fluke (that it worked properly) or if it can happen (puke) again. I picked the bank up and turned it several directions off level. It stayed good. I just don't know if it is trust worthy or not.

What does the collective wisdom here think? Trustworthy? Go for new a new float (I would go ahead and replace all 3 of the older floats if I did this)?

My fear is that if I "rebend" the tang to be more flat, that the "hole" will move a little but still be close enough to the top of the valve to grab it, yet be a little off center and jam the valve even harder. Or, perhaps, the side-to-side slop the floats have on the hinge pin is more of the blame for the jams..... As it is, this float measured EXACTLY 23mm high, so I didn't bend this tang. But, as I mentioned before, I don't know which carb was puking before I stripped the bike down. This could be a long running problem I'm dealing with even though I have new valve tips & seats.

I think while I wait for some opinions from the gurus, I'll take the carbs to my "drain can" and draw gas from #4 bowl a few times and let the needle reseat a few times & see what happens.

BTW: I have just realized that it takes quite a bit of gas to fill up 4 carb bowls. Expecially 3 times in a row.

[cajun31]

Get the new floats

I would opt for the new floats so that you are starting from good stock. If the money is not a problem I believe this would ease your worries.

[eroellig]

Can't get it to puke on the bench now...

...pulled fuel from the bowl #4 over a dozen times, several times draining the bowl cause I could drain faster than it would fill. I've probably flushed a good couple of quarts of gas through all 4 carbs in total. I did this while HOLDING the carb bank and letting the bank dip & twist a number of different directions while doing this.

cajun31 is reading my mind regarding having known stock. However, I WANNA FIRE-IT-UP & don't want to wait on a shipment. I suppose that, while it is a pain-in-the-ass to remove/replace, having carbs that (could) puke a couple of times and then replacing floats wouldn't be a mortal sin.

I may just run with what I have for now. However, what do y'all think about wear spots on the tang causing some of the puking problems we see?

Eric (closer & closer to writing a "first ride" report)

I think I'll go put the carb boots on the block

[cajun31]

Piece of mind

I still suggest the new floats. You have talked a lot about your carbs, however what kind of shape is the fuel tank in? Has it been sealed? Could it be a source of the problem? I know you have the urge to ride and it sounds like you have the overflow problem in check. If you decide to put it together and ride just watch to make sure the puking problem does not re occur because you will be risking filling your bike with fuel which will cause much larger problems for you.

[eroellig]

Re: Piece of mind

Originally posted by cajun31
I still suggest the new floats. You have talked a lot about your carbs, however what kind of shape is the fuel tank in? Has it been sealed? Could it be a source of the problem? I know you have the urge to ride and it sounds like you have the overflow problem in check. If you decide to put it together and ride just watch to make sure the puking problem does not re occur because you will be risking filling your bike with fuel which will cause much larger problems for you.

When I look in the tank, all I see is shiny metal. It looks to be in perfect shape. The tank can't be the source of the current ills since I haven't used it. I have a small plastic tank from lawn equipment (and run through a filter) that I've been using for bench checking. I'll run some carb cleaner and flush the main tank before using it just to be sure. I've just cleaned the octopus and checked it with my Mity Vac. It appears to be working just fine. All fuel lines will be new. I'm adding in-line filters. The tank petcocks work (I checked them when I drained the tank.) I'm relatively sure I have the carbs clean. I took my time when I rebuilt them (but I'm still mystified about where the two bits of crud came from that I noted earlier this afternoon.) But by now, the carbs have been flushed with quite a bit of clean gas.

I think I'll run with what I have, but on the first puke, I'll definitely order new floats. I agree, last thing I want is gas in the oil & screw up the engine.

Eric

[pggg]

ero, the crud is probably rubber crumbs coming from the fuel hose(assuming it's rubber hose), usually from the fitting ends, only a few small specks - enough to interfere with the float valves, inline filters aren't much help there, actually they even cause MORE rubber crumbs, I always say simple is best, had to sneak that annoying comment in, but new fuel hose all-round, can't go wrong..

[mro]

originally posted by pggg
I always say simple is best, had to sneak that annoying comment

Originally posted by the guy from down under who did a chain conversion to his XS with hand tools in his back yard(simple is best)


mro

[eroellig]

Originally posted by pggg
ero, the crud is probably rubber crumbs coming from the fuel hose(assuming it's rubber hose), usually from the fitting ends, only a few small specks - enough to interfere with the float valves, inline filters aren't much help there, actually they even cause MORE rubber crumbs, I always say simple is best, had to sneak that annoying comment in, but new fuel hose all-round, can't go wrong..

pggg, this is on my bench with new clear tubing. AND there is new hose ready to be installed once I put the carbs on the bike.

Eric

[Lloydo]

If you could feel a worn spot on the tang, that's what's causing that float pin to hang. I ended up taking my carbs to a shop, & they found wear spots on all 4 tangs, worse on # 4. They filed them down, polished them all. It hasn't leaked since. They also found a problem in the octopus, a tiny hole between the diapraghm, and the hose connection to the vacume advance, was clogged. Between that & the float tangs, the bike hasn't run this great since I bought it 6 years ago.

[eroellig]

Originally posted by Lloydo
If you could feel a worn spot on the tang, that's what's causing that float pin to hang. I ended up taking my carbs to a shop, & they found wear spots on all 4 tangs, worse on # 4. They filed them down, polished them all. It hasn't leaked since. [...] the bike hasn't run this great since I bought it 6 years ago.

AH HA!!!!

That is the confirmation I've been looking for.

3 new floats have been ordered from MikesXS. I'm not confident that my polishing efforts will last very long.

Thanks

Eric