More Carburetor issues!

[Midnite]

Yea, I asked him as well, and he returned my email saying:

"I have Pilot jets but no info on the xs1100. Go to my web site & see if any I list matches your sample. We are so busy with 650 parts that I never even look at the XS1100 ( some also had Hitachi Carbs )."

By the way, if someone is interested in some dirt cheap K&L main and pilot jets, I have them. Not recommended for anything but a necklace though!

[Midnite]

OK carb pro's now I am totally stuck! After all the issues with K&L carb kits, and ordering original parts to rebuild the carbs (see my countless Q's in this post) I got my pilots from Mike's, but the SAME day my wife was cleaning the garage, and she found a bag with all the original parts removed from the carburetors at the first rebuild!!! So I removed the NEW main jets, just cleaned and installed the old ones, the new pilot jets I did not even open the bag, I just installed the old (original) ones. I installed new in tank filters, new fuel lines, and new inline filters. The bike started up just fine, and ran very good. But after a couple of miles it started to run poorly, like fuel starvation poorly. I tried different things like removing the inline filters (already removed the octopus) next I tried to remove in tank filters, I tried with them both gone, and today I did the final test without any filters or fuel restrictions. The bike runs good at idle, revs up normally, but when I took it for a spin it lost power after a couple of miles, just like it is running on 2 cylinders. After a couple of minutes parked it will start up again, but will not run with full power. It took me about 35 minutes, and about 10 stops to get back home from the 2 miles. It fires right up when the "choke" is on, but at operating temps, it revs up to 4K's with the "choke" fully on.
It sure feels and sound like fuels starvation, but how can that be? Will it run for that long before it gets all the fuel out of the carbs? And when it stops, I must wait at least 5 minutes before it will start on all 4 again. I am out of ideas again! Anyone have an idea?

[ratbyk]

Fuel Starvation

Move the petcock handle to "prime" and try again. Sounds like a restriction in the petcocks which you should be able to overcome in the prime position.
If that works for you, remember to put the filters back in the system.
Ken/Sooke

[thumperjsa]

Make sure you don't have nay "odd" bends on the fuel hose. I had a similiar problem and that is what happened to me. The slightest pinch cuts off fuel.

[TopCatGr58]

Hey there Midnite,

Pop the gas cap up and leave it loose, and try it. There is a very little vent hole in the top of it, but if clogged, it restricts the flow of fuel coming out of the tank. With dual filters, you've added a modest amount of restriction. And if the tank is fairly full, doesn't take much fuel drop to create a vacuum above the fuel.

Yes, check the lines, make sure there are no kinks, and that you don't have any large loops running well below the carbs before it goes into the inlets! The Specials petcocks will flow the same with either RUN or Prime WITHOUT the Octopus inline! How do you have your lines run bypassing the Octy? From which petcock nipple are the lines running to the carbs?

I reread the thread, did you finally reset your floats to the 23mm level? Are your floats moving freely on their shafts? Are the needle valve needles able to slide easily in and out of the needle seat chamber? Is the inlet screen under the needle seat clean?

Hang in there, you'll find the culprit soon!!!
T.C.

[Midnite]

I have the prime outlets, the forward ones plugged off, I figured I did not need those, since the "on" position works the same. I have tried several options for routing of the hoses. I tried this one Option 1 also this one option 2
I also tried without inline filters straight from petcocks to carburetors, this is how I had it at my last testrun. There is no kinks in the line, but there is a loop for easier removal of the fueltank. The loop goes down the engine case and back up to the carbs. BUT, that should not matter at all the fuel is gravity feed into the carbs, so the pressure at the carb inlet will be the same regardless if there is a loop or not, right? The long of the hose as soon as it filled with gas, will have the same flow as a short one.
And yes, I did reset the floats to 23mm, and everything seem fine inside the carbs. I did rebuild the petcocks also, with new rubber seal, strange if that would restrict anything? BUT Topcat, you made me think about the gas cap because it was rusted inside, so I coated it with some Ospho, wich "stops rust, and prepares rusted surfaces for painting" It makes rusted surfaces turn into a black coating, maybe the vent hole got plugged in the prosess? The tank is full of gas, so there is not much air inside the tank. The bike can sit and idle without problems, and remember I can drive about 1 - 2 miles before the problem occurs.

[Ken Talbot]

When I hear somebody saying their bike somethimes feels like its running on only two cylinders, I start thinking about the pick-up coil wires. If you have not already done the fix, you can be about 95% sure that it in fact needs to be done. Because it is such an intermittent thing, you can chase a lot of other symptoms before you think about going after this one.

[Midnite]

Hi Ken, no I have not done anything to the pick-up coil wires, is there any way to tell if they are bad, or should I just replace them? Where is the best place to find replacement pick-up coil wires?

[TopCatGr58]

The loop goes down the engine case and back up to the carbs. BUT, that should not matter at all the fuel is gravity feed into the carbs, so the pressure at the carb inlet will be the same regardless if there is a loop or not, right?

They are gravity feed, but you are also fighting against gravity with a large loop, cause it has to PUSH the fuel back up the tube before it goes into the carbs, and if you've ever siphoned anything, you know you need to have the outlet hose lower than the siphon hose. Yes, the fuel on top does provide some pressure, but the opening where the needle valve works, and the actual area of that opening isn't that big so it also creates some resistance to flow. I think you should shorten the hoses so that if there is a loop, it's essentially level with the carb bodies, not dropping way down near the engine!

Idle is a very low fuel consumption rate, vs. actually driving it, so that may be why it's able to run, it can somehow vent enough for the small flow that's required at idle, but when you're running, then the fuel flow is much higher, and as it drops out of the tank, the vacuum can build inside the tank, IF you vent is clogged. The vent is just a little hole inside a washer looking disc inside the lock assembly of the gas cap. Try driving it with the gas cap unlocked, just don't accel too fast so as not to slosh the fuel out of the filler neck, and see how far you can go. IF it doesn't seem to starve, then push it back down, and then test further, IF it then starves, then you'll know it's the vent!
T.C.
PS, the PRIME/forward outlets are also the RESERVE, so that's why I have mine connected via a "Y" connector, and then to the carbs, so I don't loose RESERVE.

[Midnite]

Topcat, I took the cap off today, cleaned it and re-drilled the vent hole, I took the bike on 3 rides today totalling over 10 miles, city traffic, so I didn't go over 50mph, but the bike ran flawless the whole time, and it was great! Hmmm, I wonder if your petcocks are different than mine because when I had the tank off I tried turning the petcock, and the only time fuel came out of the front was at prime, on reserve the fuel came out of the rear. Just trying to use as little hose as possible. I replumbed again tonight with new inline filters. I did it like this HERE With 2 tees and 2 inline filters. I have seen 2 other plumbing directions on this site where the filters sits between the carb boots. I can not do that on mine because that is right where the petcock outlet is, would make a clean installation for sure, but will not work on mine. Right now I just have the filters hangin off the sides. I need to figure out a way to hide them without squishing the lines.

[Ken Talbot]

Midnite - there's an article here about diagnosing and fixing a problem with the pick-up coil wires. Sounds like you may have found your problem with the cap vent, but it wouldn't hurt to have a look at the wires too....

[TopCatGr58]

Hey there Midnite,

Uh, DOH, guess my Old-timer's is hitting me earlier than I thought You're probably right about where the Reserve flows from, I use PRIME position instead of RUN, cause it's completely opposite of OFF, helps me to remember to turn them a 180 degrees to OFF, and like you said, it flows out of the front pipes. So....if I had capped off my rear pipes, then "I" would loose RESERVE, yeah, that's what I was trying to say

Just glad fixing your gas cap vent seems to have fixed your problem!!!

I recoated my tank when I rebuilt/resurrected my bike, and so I haven't added inline filters, "YET",, but when I do, it'll be those little lawnmower sized ones, and they shouldn't be much of a problem to place in line, I have Indy filters, and run the lines across the closest filter, then down inbetween the outer two filters, around the bottom of the next filter, and finally into the inlet port. So....allowing a little more line/slack and mounting the filter on it's side just below the air filter should work!
Gotta get some sleep!! ...yawn.
T.C.

[xj-wxman]

XJ settings

On the XS - it sounds like the floats are set at 25mm - is it the same on th XJ? I have Mikuni carbs - never had a problem flooding before. Did the tranny rebuild and cleaned the carbs after sitting @3yrs - now it floods the cylinder/air cleaner. I did not change the float levels since the previous settings when last driven never had a problem. After 2 more cleanings - still flooding
!!! The floats have no gas inside and the float needle/seat look smooth. Any ideas? I seee no Vent tubes for the carbs like mentioned for the previous XS carbs - just the big hose venting the tranny to the air cleaner box. The wife is sick of the gas smell- ready to banish the bike outside forever!!!!


Thanks

[John]

Check the rubber tips of the float needles. I had two of them seperate from the body of the needle. The carbs would flood, and fill the airbox. Another thing to check is the O ring around the seat assembly. If they are bad, fuel can leak by them.

[RUSH]

Im up here in Lake Stevens and have a LOT of experience on carbs and pickups if you want I could stop by on a weekend and give you a hand. My record for removing cleaning and reinstalling carb banks is 45 minutes.