New Petcokcs But No Flow

[ridingagn]

Ridingagn, sorry I misread your post earlier. My experiences with in line filters is that the air pocket never seemed to make a difference for me. Although, I run my filters on the top, right after the petcock, then directly down to the fuel T's. I still have an air pocket (bubble) in the cone shaped filters I'm running and the bike runs fine.

Hey Phil,
Yeah, I didn't think the bubble would matter either. Cody (my other son aka "geniusloerts") is running the same filters on his XS and has bubbles but has no problems. This bike (Frankenbike with the problem) has the filters about 3 inches from the petcock. I know there is a hydrolics issue here...... with everyones help I'll get it figured out sooner or later. Hopefully before it warms up enough to ride.

Martin

[xswilly]

maybe you have alot of rust clogging the petcocks

[ridingagn]

maybe you have alot of rust clogging the petcocks

Tank was removed, cleaned and sealed. New petcocks, so therefore petcock filters are crystal clear. As posted before....... disconnect a hose anywhere between the carb and the tank and fuel flows from the tank in a strong steady stream.

Martin

[Larrym]

Gently Down the Stream...

Tank was removed, cleaned and sealed. New petcocks, so therefore petcock filters are crystal clear. As posted before....... disconnect a hose anywhere between the carb and the tank and fuel flows from the tank in a strong steady stream.

Martin

If you pulled off the line at the carbs and it flowed like a draft horse then I'd believe that it's either the restricted vent ( Tarzan's gasket misalignment scenario) or possibly those pesky mesh screens over the float seat are crudded up. One or the other can make backpressure which would cause the symptoms you describe.

To verify that the vents are clear is not that difficult and doesn't require removing the carbs. Airbox has to be removed but that's a problem we get used to dealing with.

First run the bike without opening the petcocks long enough for the fuel in the lines/carbs to run out. The indicator is that the engine will run like it's running out of gas cause it IS running out of gas. This drops the fuel level in the bowls as none is coming in to keep the level up. Then turn the bike off and disconnect/drain the fuel line at a convenient spot: petcocks or the inlet fuel Tee. (Your call on this one...just make sure that you're blowing just air into the line and not forcing any remaining fuel into the carb.)

The next step is likely hazardous to your health: Blow Cigarette smoke into the fuel line and watch for it to come out of the correct vent hole in whichever side you are testing. If it's too hard to blow into the fuel line then there's something restricting the flow.

If you do this test then be sure to be careful with any gasoline fumes or fluids around a lit cigarette/cigar.

[DGXSER]

Not to send you into that place Again, known as the carbs......but....If pulling the fuel line off at the inlet T to the carb bank lets it run like a mountain stream, and with it plugged into the T it will not, then it seams reasonable to say something in the carb is blocking the flow.

If it were an air issue with the tank vent, or an air lock in the line, removing that end would not relieve that air lock. Unless of course, you pul the line down enough to change the high point back to the tank when you remove the line from the carb T.

[oseaghdha]

Rockets

Fuel flow depends on siphon action as well as gravity.
I don't know why folks insist on running fuel line all over the place.
Keep them short and straight, and you will have few(er) problems.

Filters can create air breaks because of the large change in diameter and volume. I started out using big filters like that, but found that if I sucked air before switching to reserve the flow got disrupted and would not correct until I filled the tank. Caused me plenty of grief on a couple of rides.

Sorry for the crappy picture but what I ended up with is Tygon lines that run right side to 3/4 and left side to 1/2, straight down between the 3/4 and 1/2 boot respectively. I use small bore filters. About 8 inches of line per side with a spring wrap to stop kinks. There is about 1 inch of slack so removing the tank is no problem.

I have had zero problems with this setup, and no bubbles. It will pull gas from the tank all the way to nothing and never miss a beat.

[ridingagn]

Not to send you into that place Again, known as the carbs......but....If pulling the fuel line off at the inlet T to the carb bank lets it run like a mountain stream, and with it plugged into the T it will not, then it seams reasonable to say something in the carb is blocking the flow.

If it were an air issue with the tank vent, or an air lock in the line, removing that end would not relieve that air lock. Unless of course, you pul the line down enough to change the high point back to the tank when you remove the line from the carb T.

Pulled drain plugs off the bottom of the float bowls and fuel flows like a race horse. Found that if the bubble in the filters is LESS than 5mm, everything runs fine and no fuel starvation. If the bubble in the filter gets around 10 to 15mm (filling the end of the filter) then problems start. Apparently the bubble acts as a hydorlic gate that absorbs the suctuon of the outflowing fuel from the lines. I am converting to a smaller, "pointed inlet" filter that will make the bubble go back up the line to the tank. Hopefully this will facilitate a solution.
Martin

[ridingagn]

Fuel flow depends on siphon action as well as gravity.
I don't know why folks insist on running fuel line all over the place.
Keep them short and straight, and you will have few(er) problems.

Filters can create air breaks because of the large change in diameter and volume. I started out using big filters like that, but found that if I sucked air before switching to reserve the flow got disrupted and would not correct until I filled the tank. Caused me plenty of grief on a couple of rides.

Sorry for the crappy picture but what I ended up with is Tygon lines that run right side to 3/4 and left side to 1/2, straight down between the 3/4 and 1/2 boot respectively. I use small bore filters. About 8 inches of line per side with a spring wrap to stop kinks. There is about 1 inch of slack so removing the tank is no problem.

I have had zero problems with this setup, and no bubbles. It will pull gas from the tank all the way to nothing and never miss a beat.

Hey.....
I like the looks of your set-up. I agree, the shorter the lines the better. I am converting to the type of filters you have in your picture and will do the left to left and right to right process you did. As you can read in my post just before this one, as long as the bubble in the filter is small, there's no problem. But as soon as he has to switch to reserve on a ride..... big bubble and likely sitting beside the road thumping the filter to get the bubble out.

Thanks everyone for all your input and ideas...... This is a great forum full of great folks willing to help and share. Since we now have 5 XS1100's in our "fleet", I'm sure we'll be on here a bit more over time.
Thanks again,
Martin

[Ivan]

If your tank is clean, why run filters at all? The small chunks that make it past the needle and seat are going to settle to the bottom of the bowl and get flushed next time you crack a bowl drain screw. Anything small enough to stay suspended isn't going to catch in a paper filter anyhow.

My tank is not at all rust free, although it is cleaner than some and I run a pretty much stock setup, vacuum valve and all and have no problems with crud in the fuel causing problems. I even pulled the screens from the seats because they were malformed.

In my experience, which seems to grow every week (for FREE none the less ), is that the super fine rust that is finer than baby powder is what causes problems. Usually starting with plugged pilot jets. Normally its a combo with gasoline varnish build up.

All that is to say, if you run good gas, and pull your carbs once a year to clean the sludge out of the bowls, you really shouldn't need filters. If they are causing you a headache, get rid of them and waste your time worrying about more important things like tires, oil and RLUs.

[Larrym]

Carbs and Old School Wisdom

I agree with Ivan about the way the in tank petcock screens keep the chunky bits out of the fuel system. The screens are of a fine enough mesh so anything that does make it through will pass the float needle/seat if it makes it past the secondary mesh screen over the seat inlet.

The float bowls serve as a settling tank for anything that makes it through and I'm one of the guys who recognizes/uses the drain plug. I like that function of being able to open up the drain plug and purge any debris/water which has settled. Lots of the stuff I own has that drain at the bottom of the float bowl and every season at this time I make sure to use it before I put the machine into service. But then most of my stuff is old school and made when the wisdom of draining a float bowl was common practice.

If there's any merit at all to my choice of using filters it's that I chose the ones that I can see through. That and I placed them where I can easily check them visually. Also that I placed them at a low point in the fuel system where any water would settle before it makes its way into the carbs.

The fuel in my area is notorious for having contaminants like water. I have also had contaminants in the fuel that weren't exactly particulate debris: a sort of brown goo that flows through the mesh screens like they weren't even there.

I'm not sure what that goo is or if it is combustible at all. I do know that because of the location of my filters at the bottom of the loop that the goo would have to travel up and against gravity to make its way into my carbs. In effect I've made a little mouse trap where someday I hope to catch this goo for observation/study. I'll be sure to post pics of what I find/find out.

In the meantime I check the trap before each ride and at the end of the day.

I hope PETA never finds out what I'm up to.

[gareth]

This problem is not consistent either.... you can ride for an hour with no problems, then let it idle and the bowls will empty out and it fuel starves. Weird thing is it never does both sides at the same time.

Floats or float pins randomly sticking...?
Are floats free to move on the pivots? No binding thru' a full range of motion?
Float pin seats smooth and polished?

JAT or 2...

[ridingagn]

I agree with Ivan about the way the in tank petcock screens keep the chunky bits out of the fuel system. The screens are of a fine enough mesh so anything that does make it through will pass the float needle/seat if it makes it past the secondary mesh screen over the seat inlet.

The float bowls serve as a settling tank for anything that makes it through and I'm one of the guys who recognizes/uses the drain plug. I like that function of being able to open up the drain plug and purge any debris/water which has settled. Lots of the stuff I own has that drain at the bottom of the float bowl and every season at this time I make sure to use it before I put the machine into service. But then most of my stuff is old school and made when the wisdom of draining a float bowl was common practice.

If there's any merit at all to my choice of using filters it's that I chose the ones that I can see through. That and I placed them where I can easily check them visually. Also that I placed them at a low point in the fuel system where any water would settle before it makes its way into the carbs.

The fuel in my area is notorious for having contaminants like water. I have also had contaminants in the fuel that weren't exactly particulate debris: a sort of brown goo that flows through the mesh screens like they weren't even there.

I'm not sure what that goo is or if it is combustible at all. I do know that because of the location of my filters at the bottom of the loop that the goo would have to travel up and against gravity to make its way into my carbs. In effect I've made a little mouse trap where someday I hope to catch this goo for observation/study. I'll be sure to post pics of what I find/find out.

In the meantime I check the trap before each ride and at the end of the day.

I hope PETA never finds out what I'm up to.

Thanks Larry and Ivan for your good points. The reason we have filters on our fleet of XS's is personal choice and prudence. 40 years of doing my own heavy farm equipment maintenance, moonlighting as a John Deere field tech and running all kinds of engines from weed eaters to 500hp diesels, has taught me that it's a plus to have a visual indicator of what's happening in the fuel delivery system. Granted, there are filters on the tank valves, and filters in the needle valve assembly. However, almost every XS tank valve I have removed, the filter is either missing completely, or rotted into pieces. Upon cleaning the carbs on all these (5) XS's I normally find the filter in the float valve assy to be full of rusty particles and gunk. If I can catch even a little of that with an in-line filter, that saves me a carb tear down and more ride time. Changing to the tapered type filters has solved the air bubble problem, since the bubble has to collect in the pointed end of the filter and then goes on up the line to the tank. Now all we need is a sunny day !!!
Best regards to everyone on this forum. My sons, Casey and Cody told me you guys were the best, and I believe it. Thanks again for your help.
Martin