Gas leaking out of one carb

[Hardfahrer]

I just did a quick cleanup of my carbs. The jets were varnished shut from bad gas. I got them cleaned up to the point where they were moving freely but I didn't take them out as it seems the pin holding the float has been crimped to keep it in place(on both carbs). I started the bike, and it starts, but gas leaks out of the back of the left carb and it was only running on one cylinder. The one with the leaky carb. I turn off the gas and the leak stops. Seems obvious that the float might not be as free as I thought in the left carb but would that keep the right carb from getting fuel and the cylinder not firing? Any thoughts would be much appreciated.

 

[xjwmx]

I just did a quick cleanup of my carbs.

That is insufficient sacrifice to the god of carbs. For verily I say unto, unless the carbs the be thoroughly cleansed thou shalt not enter the kingdom of riderdom. For unless the carbs be as clean as though not corruption the size of a mustard seed remain thou shalt suffer eternal damnation.

 

[OakBehringer]

That is insufficient sacrifice to the god of carbs. For verily I say unto, unless the carbs the be thoroughly cleansed thou shalt not enter the kingdom of riderdom. For unless the carbs be as clean as though not corruption the size of a mustard seed remain thou shalt suffer eternal damnation.

haaaaahahahahaha

 

[xjwmx]

It's like sacrificing half a lamb and putting the other half in the freezer.

 

[Hardfahrer]

Thanks clown and peanut gallery. I will print your response on soft tissue paper and put it to good use whilst cleaning my rear.

 

[xjwmx]

LOL Well then, you can just stay a pedestrian.

 

[gixxsta04]

If the gas is pouring from the overflow there are basically 2 possible problems.

-Problem A: The float valve is clogged and cannot shut once the bowls are full. Try tapping on the float bowls with a hammer to free the debris. If this doesnt work you will have to dissasemble and clean thoroughly.

-Problem B: The float has a leak and has filled with fuel and sunk to the bottom of the float bowl. Remove and Replace the float.

 

[Hardfahrer]

Thanks gixxsta04.
Do you think a stuck or sunk float would cause a no fuel situation in the other carb? I just want to make sure that when I tear them down again, I'm not missing something.

 

[azman857]

Problem C: Varnish of old/bad gas has built up on the float pins and frozen the floats in the down position. they can't raise u to close the float valve. Variation Same thing has happened to the needle in the valve, varnished in place and cant move. It happens. Either way one has to disassemble and clean. Might as well clean the carbs all the way since they are disassembled.
problem D: worn float valve. replace with new, viton tipped valve assemblies.

 

[azman857]

what year is the bike? some have 2 hoses to the carbs later ones have 1. Vacuum shut-offs, manual shut offs? clogged filters. give us something to work with here.... just sayin...

 

[5twins]

I'm assuming these are 1980 or newer BS34s because of the float pin situation. None of the 650 carb float pins are crimped in place but the BS34 ones are a wedge fit on one end. One end has like a nail head on it and the pin diameter for about 1/8" below that is larger than the rest of the pin. It wedges into it's post. The pin must be GENTLY driven out from the opposite end. I use a 1/16" pin punch. If the pin won't start moving after a few taps and the float is sticky on the pivot, I assume the post holes are gummed up as well. I apply carb cleaner or penetrating oil and heat, then attempt to drive the pin out again. Take care because the posts are just cast pot metal. If you break one off, that carb is ruined.

 

[littlebill31]

www.amckayltd.com/carbguide.pdf

Problem E: The float height is not adjusted.
I'm betting on a dirty ass carb though.

Doing a "quick" clean is sometimes worse then doing nothing. All a quick cleaning, or just spraying some cleaner in the carbs does, is break free little pieces of varnish and crud. Which then finds it's way into a port.
Imagine rinsing out your coffee pot in the sink. Ya, the pot is now clean, but look in the sink.

 

[Hardfahrer]

Azman857, it's an 82 with a single feed tube that T's off to each carb at the bottom.
Looks like I'll need to do a proper rebuild. Can anyone identify the carb from the pick? Or do I just give the guy the model and year.

 

[azman857]

See box 12 and click on carbguide or look on the top for tech. go for Carbs section. Look for the carbguide. If your carbs are originals you should have BS34's with plastic floats. READ the carbguide and invest in a carb cleaner dip. Once your bike will idle and not die, run some Seafoam in your gas. I swear by it, not at it. It will get out what the other carb cleaners left behind. It will make your bike run a bit worse for a bit. but stay with it ,and in my expereince, will run better. It is NOT a cure all or a subsitute for a carb clean. Just prevent a running bike from needing more of them. Use a good fuel filter inline too.

 

[Patches]

It's a BS34.

On a side note, you come on here looking for free help and don't supply any type of intro while giving insufficient information. I'm surprised with your attitude you didn't get more replies like xjwmx's. This seems to be a trend lately....

There is an excellent carb guide in the tech section that will answer all of your questions and then some. Do yourself a favor and read it. You will be a better XS owner for doing it.

 

[xjwmx]

I'm surprised with your attitude you didn't get more replies like xjwmx's.

Everybody is just reiterating what I said originally, although in more materialistic terms.

 

[gggGary]

Small add ons. The float valve is held in place by a screw and bracket. when those are removed the valve body can be separated from the carb body there is an o-ring that seals it. The o-ring is BAD always, every time. even if it "looks" good it is brittle and is letting gas bypass the valve. Remove it and check it, it will break when you go to remove it because it is brittle with age. A local auto store usually has one that "will fit", don't use "too big of one" because it will be hard to get the valve back in the body. A little grease or silicone will help get it back in. Clean the screen while you are there. It is common to clean carbs and then have to do it again and sometimes again as all the rust and varnish in the gas tank and fuel lines is loosened and gets dragged through the fuel system. Expect a few more "running" issues till all the crap is cleaned out. Draining the float bowls a few times over a week or two (easy on your bike) will reveal what I am talking about. No matter how thorough I am with fuel system cleaning a float bowl drain reveals at least some more junk waiting to plug the carbs. Oh welcome to board, and now you can go wipe again.

 

[5twins]

and another add-on - jets don't move, lol.

 

[Hardfahrer]

Patches, thanks for the info.

On a side note, I find it funny that I come here looking for help and first I'm mocked and then laughed at, and now I have to defend myself. Sorry for the insufficient info and lack of proper introduction but I'm new and thought I covered it.Also, sorry you didn't think my attitude was justified, didn't mean to be so trendy. Have a good day.

 

[claybear]

I'm having the same issue, except I've read all the info I can find, thoroughly cleaned the carbs, replaced the float needles, made sure the floats moved freely and even checked to see if the floats sunk or bubbled in a tub of gas.. So I want to know if anyone has any other ideas as to what could cause the carbs to leak through into the air filters? I have an 81, so I believe they're the Bs34's.