frustration with my 81xs11

[Cykotic]

my bike is driving me up the wall. Somedays it runs just fine and others it doesn't. Lately the problem i have been having is that i can be riding down the highway, city street, etc. and the thing with start to sputter and cough and the die like it's flooding out. I have repaired the coils, checked the advance, the carbs are ok, battery is fine, and the bike still does this seemingly whenever it wants to. Finally last nite, i was riding and it seems to die out more like a fuel starvation this time and it does this three times while going down a six mile stretch. However after i sit for a minute on the roadside it will fire up again, but only if i use the choke. Then with the choke on it sky rockets the rpms up to about 5,000 to 6,000 for a second until i turn the choke off. Then wallah, the bike is fine again. Any ideas or suggestions would be appreciated. I think i've read all these threads and am still just confused. By the way This forum is the greatest and has really helped me more than i can say and is greatly appreciated.

[TopCatGr58]

Hey there Cykotic,

Well, you say the carbs are OKAY, but didn't really go into detail as to HOW you know they are okay. Have you personally cleaned them? The symptoms you described sound mostly like fuel starvation alright. However, when you hit the choke/fuel enrichener, it does improve/increase in rpms, so more fuel is getting in there, so it doesn't sound like it's NOT in the fuel bowls, as in not flowing from the petcocks to the carbs....btw, do you have the Octopus? You didn't say, nor does your profile specify which model you have SH or H?

The pilot circuits and these carbs in general are known for getting clogged, gummed up, and clogged pilots can definitely affect the just off idle and throttle response! Has the brass caps on top of the front edge of the carbs been removed/drilled out to allow access to the pilot screws? IF NOT, then the pilot circuit can not be relied on to be clean/clear, even after a recent cleaning! You may want to try some SEAFOAM!?

But it could also be electrical, we had a recent occurance on a recent rally where an Xsive's bike was cutting on and off, turned out to be a bad tip over safety switch. It's under the tank, near the front, above the coils, and is labelled UPPER, unplug it and then ride the bike and see how it behaves. IF it cures the problem, then it's a faulty switch. It's to kill the bike's engine in case of accidental tip over/fall. It's not critical for operation, but is a good safety feature! HTH.
T.C.

[Dragonrider]

Might also check the vacuum lines to your petcocks or octopus (special) and make sure the are not split. Then make sure the petcocks (or octopus) actually let fuel flow when vacuum is applied to the vacuum lines.

On a standard, check the vent line to the gas tank...pinched or clogged and your bike will starve for fuel. On a special, the vent is in the cap (check that too).

You said you checked the advance...did you check the pickup wires while you were in there?

Good luck!

[skids]

Re: frustration with my 81xs11

Try opening the gas cap, running the bike around, to see if it isn't the tank breather. When they clog, they quit flowing fuel.

Originally posted by Cykotic
my bike is driving me up the wall. Somedays it runs just fine and others it doesn't. Lately the problem i have been having is that i can be riding down the highway, city street, etc. and the thing with start to sputter and cough (snip)

[uk1.1s]

Tank fuel cap

Agree with Skids.... sounds like the old "clogged breather hole" trick famous in old British sports cars, old Austin Mini's and ... for some reason... a lot of 70's and 80's bikes.

There's a tiny vent hole in the fuel filler cap (or on the bracket surround visible when you open it up) which gets clogged up with dirt... once it's sealed any fuel leaving the tank causes a vacuum... which increases until it's enough to stop fuel flow.

Stopping for a little while lets enough air sneak past the dirt to realse the vacuum and all is fine again. Drove a mate of mine with th Mini mad for years until he worked that out. Had a car that used to run 5 miles only - unless left to "rest" a while. He just thought it was lazy

[superdave]

HAD AN OLD OUTBOARD MOTOR DO THAT!

[Cykotic]

Hey, thanks for all of the advice guys. I think, or so it seems as of yesterday, it was the vaccuum lines. I replaced all of them last evening and the bike seems to be running fine at the moment, but as usual i think i will give it perhaps a 30 mile or so ride today and check to see if it truly is fixed. Mainly because on all of my prior attempts it seems to run fine right after whatever i do, then it starts the same symptoms all over again. I will let you know what happens with it today after the vaccuum line replacement. By the way, after i replaced the lines last night, it ran good enough to get me pulled over twice in 15 minutes by the good ole atwater p.d. Thanks again.

Also, it's a 81 xs1100H, with Fatboy pipes, and man it is a mean sound when you let 'er rip.

Oh yeah, another thing i also did was to place a towel under my seat, just in case i was shorting out on anything.

[Cykotic]

by the way, i also removed the tip over switch temporarily just to eliminate that option. You guys amaze me how thorough you are and quick in your responses and i thank you all for that.