carb issues after rebuild and pod filters

[country guy]

1979 xs1100 after rebuillding carbs and replacing air filter box with individual pod filters gas is backflowing out of carb inlets and out of carb vent tubes which as of now are just hanging down. wondering if vent lines from carbs need to be ran into intake for vaccuumm not sure if i spelled that right lol. any tips or help would be appreciated. im thinking its something with the vent lines not being hooked up properly or maybe somehow foats got messed up thanks

[bikerphil]

The vent lines for your carbs should be open to atmosphere like you say they are, no vacuum or plugs on them. Are you running in line fuel filters?, if not, some crud could be finding it's way into the needle/seats. Other possibilities are floats hanging up on bowl gaskets, leaking floats (sinking), bad fiber gasket on needle/seat assembly. BTW, the lower carb T's are for fuel inlet and the upper are the bowl vents, maybe have them backwards?

[Gallaecus]

is it a special? if you have the lines to the petcocks backwards, i think it will leak out the carbs. point your vents up if you can rotate the tee easy and put a chunk of hose with a small breather (gas filter.) make sure you connected everything correctly.

[crazy steve]

Well, the vent lines need to be above the float bowls, and you should put some sort of filter on them. They originally hooked to the factory airbox.

Fuel running out means your float valves aren't sealing, float level is too high, floats are hanging up on the gaskets, or bad valves.

The early carbs have the all-metal valves, and the slightest bit of crap will cause leaks. If they haven't been replaced, you probably need new ones. The aftermarket gaskets can be slightly larger than OEM, trimming the excess inside the bowls will prevent hang-ups. Float level should be 1" if you still have the brass floats, make sure both sides match and they move freely.

And these carbs need to be clean; pulling the bowls and blowing them out won't cut it. If they're not white-glove clean, expect problems.

[bikerphil]

If you used new float bowl gaskets from an aftermarket rebuild kit, chances are the sides need trimming down and/or the brass float bulbs need to be slightly bent inwards away from the sides of the bowl, common problem for these carbs, floats binding, JAT

[country guy]

ok tomorrow ill pull the carbs clean and recheck eveything, install fuel/vent filters and double check all lines. thanks for the helpful advice il let yall know how it goes

[conquest87tsi]

Not sure how you setup you pod filters, but I used 3" long silicone hose as a velocity stack between the carbs and filters. Hose fits over carbs, pods fit over hose. You'd have to measure to get the right size. I got bigger pods to fit over the hose so roughly 6mm diameter larger than the carbs.

What I did for the vent lines was drill a single 1/4" hole in each of the two middle 3"long hoses and insert a steel high pressure valve stem(one with nut and washer) and ran the vent hoses to them. It is a lot cleaner than having a $hit load of little filters. I remember someone had a unique design for eliminating a seperate crank case breather as well.

[conquest87tsi]

Oh and some people have used the factory velocity stacks from the air box. You could do the same with those.

[XS1100_OEM4ME]

hi, CG

Hi Country Guy, don't know if you sall my PM, but BikerPhil is thinking about comming over this way Sat or Sun to meet up. Let me know if you want to meet also and if you would like us to see if we can give a hand with your bike? Lon

[bikerphil]

Yep, me and Lon are carb experts. I'm heading over to Lee county this weekend, let us know, be glad to help out bro.

[GLoweVA]

Darn, If only I still lived in Naples, I'd ride up and visit too.

It's always nice to have fellow XSives in the area to help like this.

TC, KeithH and Nightengale and I sometime help each other out here in SE Va.

[country guy]

wow i had the vent lines and fuel lines backwards lol maybe to many beers during reassembly lol but carbs needed to come off any way for vent filters. im not sure if my bike will be done, but would love to meet up with yall im off tomorrow so ill have all day to mess with it and ill let yall know

[DiverRay]

You can run a single filter at a "Y" up under the tank for a vent. You MAY not need to pull the carbs again, as you were dumping fuel in as fast as it would flow. You may be able to get it running well, and ride up.

[bikerphil]

wow i had the vent lines and fuel lines backwards lol maybe to many beers during reassembly lol but carbs needed to come off any way for vent filters. im not sure if my bike will be done, but would love to meet up with yall im off tomorrow so ill have all day to mess with it and ill let yall know

Glad you got it figured out, It'll be good to meet up sometime this weekend,

[Nightengale]

Oh and some people have used the factory velocity stacks from the air box. You could do the same with those.

I use them on mine and they work great, with the pod filters.