carb overflow

[ikeholt40]

I didn't have any problems with my xs 1100 special before I removed my fuel tank to get it painted. I wish I would have installed fuel filters before starting the bike again. But I didnt, and now the 4th and 3rd carburetors are overflowing into the air intake. I have tried turning the petcock to off and prime to loosen the rust or grime and this didnt work. I also tried blowing air into the fuel lines. I have installed fuel filters and I am wondering what else I can do before removing carbs.
Where can i find info on removing carbs on an xs 1100 special.

[John]

I take it you don't have a repair manual. That is required if you own an old bike. They are available in bike shops and on ebay.
The first step is, if the bike still runs, is to run the engine a bit, with the fuel turned off, to use up what fuel is still in the bowls and in the lines. That will help prevent spillage. Once it stalls from lack of fuel, the tank can be removed. You'll need to remove the seat, first. You will see a bolt holding the rear of the tank to the frame. Remove it. Lift the rear of the tank, and note the routing of the fuel lines. Remove the lines from the petcocks, and lift and slide the tank to the rear. If the petcocks leak a little, then
just store the tank with the rear of it elevated. That should move the fuel away from the petcocks. Next, remove the bottom of the airbox, and set it aside. Loosen the four clamps that hold the airbox boots to the carbs. There are three bolts securing the airbox to the frame. One is on top, and the other two are on each side of the airbox. Removing the battery can help make some room for the airbox to slide to the rear. Once the attaching hardware is removed, then work the airbox up and down while pulling it to the rear. That should seperate it from the carbs. if your bike is a 79, then there will be two small hoses that are attached to the top, front of the airbox. These are vents for the carbs. Remember , these need to be reattached when the bike is put back together. Do not just cap them off. Remember there position on the carbs,they are the upper set, when you get them disconnected. You don't want to use these hoses as the fuel supply. If the bike is an 80-81, then it won't have these hoses. The large hose is the crankcase vent. Remove it also. Once the airbox is slid back, then you can loosen the clamps holding the carbs to the intake boots. Once that is done, then throw a leg over the bike, and grab the carbs and start to work them up and down, and pull to the rear. They will seperate from the boots. It just takes a good bit of pulling and working up and down. Once they are free, slide them to the left to remove the throttle cable, then remove them by continuing to slide them to the left. It will take a bit of finagling, but they will come out. Reverse the procedure to install them. Remember to connect the throttle cable befroe the carbs are fully reinstalled. A little lube on the opening of the carb boots will help to reinsert the carbs back into the boots. That will take A LOT of finagling, and words you Mom won't approve of, to get them back in.
Good luck...

[skids]

Something you can try that goes along with what John suggested:

You want to flush out any offending particles that may be preventing a good seal at the needle valve/seat area. Get a tray to catch fuel, place it beneath the carb. Open the drain tap at the bottom and empty the carb. This opens the needle valve all the way by dropping the float. Turn on the petcock to PRIME long enough to flush out any particles. Turn the petcock back to OFF (special) or RUN (standard) and close the drain tap. Turn the petcock back to prime to fill the bowl and the back to OFF or RUN. Do this to each carb. Dropping the floats that low may rotate them to where they could stick due to any corrosion on their pivots, so it may require that you thunk in the float bowls with a length of wood (and a hammer?)

If your automatic fuel shut off isn't sealing good, you might want to disconnect the vacuum hose from the manifold side (to the octupus or petcock) and blow into the hose (2 for standards) to seat the O-ring on the plunger diaphragm(s). This could work out for storage purposes but may not to well enough for a permanent fix, depending on what the real problem is.

You can check for petcock leakage on a standard, of course, by switching the petcock to run, disconnect the fuel hose (no sparks or flames!) and see if the hose continues to leak.

[prometheus578]

John and Skids pretty much covered all that you need to know. If you still have probs, as a retired Infantryman, I can help you out with the "mechanics language" part.

[skids]

There are more reasons for carbs overflowing, but do the easy things first! =:-)

Originally posted by prometheus578
John and Skids pretty much covered all that you need to know. If you still have probs, as a retired Infantryman, I can help you out with the "mechanics language" part.

[John]

mechanics language

Being a former sailor, I can can cuss with the best of them too.

[wildbill]

After all of that something else you might want to try with the drain bolt out is to take a can of spray carb cleaner and aim the spray tube up through the hole and then give it a good shot.It might help if not be prepared to pull the carbs. Good luck.

[fredintoon]

get the book!

My Clymer's was still on backorder the first time I pulled the carbs off my newly purchased non-running XS11SG.
Got 'em off OK, cleaned half a swamp's worth of crud out of them too AND got the motor running but I shoulda waited for that book.
John's instructions are accurate and he does say "remove the bottom half of the airbox"
What he omitted is the dire warning in Clymer's.
"Do not dismantle the top half of the airbox" Clymer's says.
Oh Lord are they right on that one!
What a fiddlesome timewasting bitch of a job it was to put the top half of my airbox back together again.
Fred Hill, S'toon.

[prometheus578]

old fuel line

A lot of carb probs on older bikes are caused by old decaying fuel lines, especially after removing carbs, tanks, etc as you have done. When you removed the fuel lines from the tank, did the inside core of the fuel line look cracked and brittle. Where the lines hard, brittle, and not pliable? What happens a lot of times, when hooking everything back up, chunks of the old rubber line break off, go with the flow, and lodge between the needle and seat in the carb. Just takes a really small piece to ruin the works. In your scenario, the fuel filters would have been installed after the fact.

I've never understood when other's say to move the petcock around to loosen rust, etc. Fine if you want to loosen the gunk in the petcock, but have the line draining into a bucket, not into your carbs. (My intention here is not to discredit anyone else's advice, far from it. I just have never done this technique) It may work for smaller particles, but I don't think that's the case here.

If needles are gummy or stuck, filling the fuel line with carb cleaner may help to dissolve some gunk, but as your carbs were flowing before, I don't think you have a "sludge" prob.

Regrettably, at this point, I'd remove the carbs. (And get new fuel line 'cause your old stuff is 25 years old.)

[prometheus578]

What Fred Said

Tell me about it. Been there... Dumb that!

[wildbill]

They call them " little monsters" and they are right. Been there and dumb that. Gives you plenty of time to think up new names.