Hit the wall

[desert1]

I've had this bike for 13 years now, had run into many issues some turned out to be simple, some complex, and solved them all mostly thru the groups help but I may have hit the wall this time.

I will start at where it MAY have all began....riding into my shed the other day I caught my left footpeg on a crate in the way which pitched me and machine sideways at a 45 deg. angle, not enough to crash or drop the bike....the bike kept runnin while was angry at myself for leaving the darn crate in the way....after a min. I righted the bike and myself, shut it off and parked it.....ever since Ive only had the bike run on 3 cylinders..

I've had the carbs out today and yesterday and found nothing amiss....whats happening is #3 cylinder is the culprit, its not getting enough fuel.....theres a ton of spark as checked many times and used various plugs to double check, the spark boot is good, compression is 130 and I checked with the carbs off and turning over the engine to compare air intake at the carb boots, plenty of air intake at all carb boots.....so spark is not an issue, compression is not an issue, and right now I'm hooked up to syncronising gauges and there all balanced includiing #3 cylinder....each time I compare heat coming off the pipes all are hot but #3 which is just warm....and when removing the plug to check it its only slightly wet with fuel.....

More info on the carbs, the floats have been measured and the floats are free and not sticking....when removing the carbs for dissassembly I drained the float bowls and they all had lots of fuel.....these carbs are super clean as well as jets and emulsion tubes...... I have several other carbs to replace #3 but I dont see the point......a lot of frustration with this issue and it may be the straw that puts the XS back in the corner of the shed ....

If you have any thoughts or ideas they certainly would be appreciated....I had another thread 2 weeks ago on my axle problem and changing the 17 inch wheel to a 16...that has been installed and is fine, now all I need is 4 cylinders running once more!!! And the weather is so great here, man this @#$%.'s....ugh
Bruce
78xs1100

[GLoweVA]

Sounds like fuel in is okay, but fuel to the carb is not.
Does #3 get hot while the choke is on?
In other words is the 'enrichening' circuit working on #3 carb.
That might help narrow down the problem a little.

Maybe the impact/jarring caused something to come loose/break in #3 carb. (even some spec/gunk that is now cloggin something)(or even the idle mix screw tip getting broke in the hole)
Check to make sure all the parts in #3 look/work just like in the rest.
Like the little brass tube that goes down in the hole of the carb bowl.

Could there be an air obstruction upstream of the carb? Like in the filter or carb inlet boot? Easy test for this would be to run the bike with out any filter/airbox on, just straight carbs sucking air. Be careful not to suck anything bad in.

I know these suggestions may be grasping at straws, but it's got to be something, right?

[cywelchjr]

Try swapping plug wires between 2 and 3 as they are paired and if fuel is fine and the carbs are fine then the likely culprit is spark. If the problem switches to 2 then the problem is something with the wire or boot.

[GLoweVA]

Edit !

Sounds like fuel in is okay, but fuel to the carb is not.

Meant to say: Sounds like fuel into the carb is okay, but fuel to the cylinder is not.

Cy, It sounds like his is more of a fuel issue, but I do like that simple test to totally rule out the spark/ignition completely.

[cywelchjr]

Meant to say: Sounds like fuel into the carb is okay, but fuel to the cylinder is not.

Cy, It sounds like his is more of a fuel issue, but I do like that simple test to totally rule out the spark/ignition completely.

Based on the plug being wet, it sounds like fuel may be getting to the cylinder, which may be no spark, the test is easy enough. Another would be the swap the plugs between the two cylinders as well.

[BA80]

Based on the plug being wet, it sounds like fuel may be getting to the cylinder, which may be no spark, the test is easy enough. Another would be the swap the plugs between the two cylinders as well.

theres a ton of spark as checked many times and used various plugs to double check, the spark boot is good,

...................But your right Cy, something has to be missing...fuel, compression, or fire.

[motoman]

Sounds like something secondary ignition-wise finially jarred loose and not a good connection..........better there at the man-cave than a long ways from nowhere.....

[Lbrown311]

Definately agree with the spark check. Initial thought was possibly the idle mixture screw as well. Those would be my first two checks. It is definately getting fuel, so it is missing oxygen or spark.

[tarzan]

Could you have dented the header for number three causing a restriction?

[Shockman54]

check to see if your mixture screw tip broke off. same thing happened to me.

[ViperRon]

I know this does not quite fit the symptoms as you have said that the spark pug is getting gas but I have a theory. Dumping the tank on the side could have jared loose something and there is the possibility it is in the T not the carb. You could check this if your bowls have the drain plug by just checking for flow. You should do as CY mentioned and do the ignition wire swap but also swap the plug at the same time.

[GLoweVA]

I know this does not quite fit the symptoms as you have said that the spark pug is getting gas but I have a theory. Dumping the tank on the side could have jared loose something and there is the possibility it is in the T not the carb. You could check this if your bowls have the drain plug by just checking for flow. You should do as CY mentioned and do the ignition wire swap but also swap the plug at the same time.

Ron, He says he's getting enough fuel into the carbs.

...when removing the carbs for dissassembly I drained the float bowls and they all had lots of fuel...

I know we're all trying to come up with ideas for him to try, so I don't want to be discouraging.

[skids]

Replace that spark plug and try again.

[trbig]

If you've got the carbs off and the bowls, with the carbs upside down and fuel line attached to the tees, you can blow into the gas line as you raise each float and feel if one is obstructed.

As others suggested, I'd try swapping plug wires from 2-3. If that doesn't change the miss, swap the plugs. If you swap the plugs and the wires, you still don't know which one it was if the miss moves. Just one thing at a time.

[desert1]

just maybe

First, let me thank all the replys and ideas that have been thoughtfully sent into our terrific XS11 site on my behalf....Secondly, may you all have a Great "USA"day despite the oppresive heat I'm hearing about and loss of power in large sectors of the country.

Back to this stubborn machine of mine; twice in the last 5 yrs since I installed the stainless 4 into 1 supertrap muffler on the bike I've had problems with it.....I'll describe; the two times I ran out of gas (gas gauge has never worked) the bike backfired before rolling to a halt...upon getting gas into the tank the bike refused to start....and after much detective work it turned out the backfire was the key, it loosened-up the crud and soot in the chamber and plugged the supertrap rings so the engine couldnt breath...when I removed the rings and pulled out all the crap in there and more plates in with spacers as an addition it stopped the problem....I'm hoping this problem may have recurred just a thought ...as when the bike slid into the garage it hit the muffler. One thing though is different, 3 cylinders are runnin and whats odd about #3 cylinder is that it was my best has the highest compression, draws the most air.
So far have checked the idol screw tips there all pristine, will try switching plugs again and crossing leads....yah' know the kicker to all of this Guys, is that I've allways stored the bike, kept it clean, looked after the wiring and carbs and the bike is quite sharp lookin.... I know, it sounds like I'm whining so I'll shut-up and get back to the garage get this thing runnin....let you know what gives....HAPPY JULY 4th from Canada. Bruce