New here , just snagged a 1980 xs1100

[TDodge7]

and i just pulled the float valves even the little screens on the ends are perfectly clean , yet i have 1 cylinder that doesn't get any gas unless the choke is on , and one that sometimes gets gas . while the engine was running we unplugged the synch plug on cylinder 4 and every time we sprayed carb cleaner into the nipple on the boot that cylinder would fire up . so what could possibly be the problem ? this one is new to me

[DiverRay]

CHECK THE VENT TUBE FOR 3&4. SPRAY CARB CLEANER THOUGH IT FROM INSIDE THE CARBS!!! If the vent is blocked, it WILL cause the bike to run rich!
I would also check the spark plug caps with a VOM. If you have one over 5.5K Ohms, it needs to be replaced. They can be ordered NEW from NGK, and almost any GOOD parts store can get them. You DO NOT need to pay the "motorcycle shop" price. I think they cost me about $5.00 each for resistor, and about $3.50 each for the NON-RESISTOR caps I now run.

[scalded dog]

On the pick-up coils moving them around probably won't help, the wire breaks clean inside the rubber coating, in the tech tips, you will read how to pull on the wire coating to check for a break, also the diaphrams inside the carbs may have a couple pinholes in them. Later 'Dog

[TDodge7]

the diaphrams don't have any pin holes . all the openings in the carbs are clean .and the problem seems to be that no fuel makes it to cylinder 4 even tho the carb appears to be 100% clear . i did check the pickup wires by pulling on them , and flicking them , and bending them , just about everything , and even the voltmeter says the wires are good . i don't seem to have any problems with spark . just this mystery problem with the carbs .

[scalded dog]

the only thing left that could keep gas out of the #4 cyl, is the jets, or there is no vacuum pulling diaphram open, which could be a valve not workin properly, since there are no pinholes in the diaphram. Later 'Dog

[scalded dog]

...just remembered, I didn't get a good seal on one of my diaphrams one time, so it was acting up, somehow I had got part of it folded under the cap. Later 'Dog

[TDodge7]

all of the diaphrams are in great shape , i don't think thats it . like i said , if i remove the rubber cap for the synchronizer on the carb boot i can squirt carb cleaner in and that cylinder comes to life .

[Thee_oddball]

If i remember correctly the stator does not start working till 2k so a crap battery would effect low RPM I think

[scalded dog]

The diaphrams are what opens to let the gas go thru the emulsion tubes and the jets, spraying carb cleaner in the synch port would go directly to the cylinder, there for coming to life, but then the diaphram is not opening to let the gas leave the bowl and go into the cylinder, it has to be the diaphram's not opening up. Later 'Dog

[tarzan]

Do you have the airbox or pods off and can visually see that the slide on #4 doesn't go up at all?
Also, if you had a valve stuck open it would not start firing on that cylinder even when spraying fuel in the vacuum nipple.
If the valve works intermittantly then it should fire intermittantly even without priming it.

[TDodge7]

how well should these bikes run with the air boxes off ? some bikes run fine without and some have to have them for the resistance . it'll be alot easier to figure out whats wrong if i don't have to keep putting the air box on . i can't start it up right now (too late) but i'll try tomorrow and see how it does , i cleaned the carbs again , but nothing changed . i switched the insides of carb 3 and 4 just for the hell of it . i did notice that the air screw on carb 4 was in way farther than the others , i unscrewed it a little to see if it was stuck in the bore like i saw in tech tips . it wasn't , i just backed it out till it looked like the others , my synchronizer is ordered but not here yet . i always seem to end up with bikes that have the weirdest problems . i really hope i can get this thing going .

[kirmit77]

video= dirtbike

man after watching that video i could have sworn you were riding on a dirtbike thru the yard!!

I took my carbs apart not to long ago (about 2 months ago really) and tried to clean them with just spray crap but i found a guy here in texas that does a really good job and did a set on my KZ1000. www.wgcarbs.com

$359 and your carbs are like new!
Should check into him
Im tired of messing with mine and im sending this xs11 set to him!
goodluck

[DiverRay]

all of the diaphrams are in great shape , i don't think thats it . like i said , if i remove the rubber cap for the synchronizer on the carb boot i can squirt carb cleaner in and that cylinder comes to life .

With the carbs on, and NO AIR FILTER, try to start the bike and then shut it down. Now pull the 10mm bolt on the bottom of the #4 carb, and see how much gas comes out? Do this for #1 as well, so you have an idea of how much SHOULD flow out. If you have no gas, you need to find out why. If you DO have the same amount of gas from both carbs, you need to find out why you DON'T have gas flowing at low RPM's

i just backed it out till it looked like the others , my synchronizer is ordered but not here yet

Without a PROPER SYNC, you will NOT have it running correctly. I've tried, and usually get three of four running. It sounds to me as if you are "dragging" #4 with the other three carbs.

[TDodge7]

well i spent all last night making sure the carbs were clean enough to eat off of . every passage is clean , the little filters are clean , float heights are within spec . i even switched all the jets from carb 4 into carb 3 . hooked everything back up except the air box . then i fired it up ....and it's exactly how it was before . but here's the kicker , the diaphram and slide move just like the rest of the carbs , but it still doesn't run on 4 . if i put my hand over the back of carb 4 that cylinder fires right up and stays running for a few seconds . now keep in mind that the diaphram , slide , emulsion tube , and jets from carb 3 are now in carb 4 and i have the same results . i know for a fact the main jet passages and pilot jet passages are clear . so i can only come to the assumption that my engine is infact clogged with magic , because that seems to be the only way to explain it .

[kirmit77]

so i can only come to the assumption that my engine is infact clogged with magic , because that seems to be the only way to explain it .

THATS IT!!! darn magic always messing with all of us.... just like those little gremlins!!!

hey, atleast yours runs and is all together...