one cylinder not working...but why?

[CRXSi90]

I fired the XS11 up today and let it run for a minute then sprayed water on each header pipe. 3 of them fizzed right away, but one didn't. It did evaporate slowly...I'm not sure if that was heat from the other parts, or if it was "kinda" working.

I pulled the spark plug wire of the plug and stuck a screwdriver in and set it so part was maybe 1/4" away from the block. It wasn't a real fat spark or anything, but it was there. I did the same on one that did work, and I got the-same-or-worse results. Thus, I believe that we have spark. Does that make any sense?

So, I'm guessing the jets in the carb are clogged, right? Would it do me any good to run a bottle of carb cleaner through the tank? I don't really want to tear down the carbs...knowing my luck, the carb boot things going to the engine will come off w/ the carb. They already have cracks. I suppose I could just pull the float bowl off and tinker that way, eh?

Am I on the right track, and what would be my best plan of attack?

Thanks!

p.s.

I'm thinking of ordering air and oil filters from Dennis Kirk...anything wrong w/ that?
Fram Oil Filter:
http://www.denniskirk.com/jsp/produc...Id=&leafCatId=
Uni Factory Replacement Air Filter:
http://www.denniskirk.com/jsp/produc...Id=&leafCatId=

[dragxs11]

Did you use the choke? If so, I think it was pgg who enlightened me about a passage way in the bowl used for the choke. If it is clogged, the cylinder won't get enough gas. After it warms up, and the choke is off for awhile it will get better. Does that sound like your problem? If so, you need to take that bowl off and unclog that passage. It is very small so you would need something fine, but fairly ridged to stick in there.
Fram oil filters are good, but the o-ring usually comes wadded in the box, and can be hard to get seated properly.
Don't know much about the uni filters

[CRXSi90]

Hey, thanks for the reply! Now that you mention it, I think it did run better once I turned off the choke on my ride home a month ago. It wasn't great, but i bet that was partly because the vacuum advance hose was cracked where it goes onto the carb port. Well, at least I have a place to start now!

A fellow member recommended UNI, so I feel pretty safe. Cheaper than K&N, yet they said it held up for them.

Hopefully I'll have an update before the weekend is up!

Kevin

[Pat Kelly]

I had a bad pilot jet on my E. It ran on 3 cyl up to 4000 RPM the when it transitioned to the main jets the dead cylinder would kick-in.

[thumperjsa]

I had one cylinder that was getting spark but did not heat up. Turned out to be a vacuum leak in the intake near the cylinder head.

Air was being sucked into the cylinder but it was to lean to fire up is my theory. I replaced all the intakes and have not had the problem since.

[CRXSi90]

Pat Kelly, I'm planning on pulling the float bowl down while the carb is still on the bike...is that something I'd be able to clean without pulling off the carbs? I know more-or-less what a carburator does and how it works, but all these passages confuse me some. The jets your talking about are the ones that screw in from the bottom, right? What are those brass things that are in the main passage where the air goes that are on the engine side of the carb, and face the engine?

Thumperjsa, you are refering to the rubber intake boot thing between the carburater and the cylinder head, right? Mine are in pretty poor condition, so I suppose that is just as likely.

I didn't get to dig into the carb today...my dad wanted some work out of me...go figure! (its my day off, I wanna do stuff for me!) oh well. At least I did get the screws on the bowl cracked loose (they seemed tight, almost like they haven't been messed with before...that would be good, I think...un-raped carbs!). Hopefully tomorrow I can take a peak and see whats up.

1 question: Is there any way to tell if a main jet is clogged? (other than a lack of power, which is hard to tell when you don't know what your bike is capable of...)

[dragxs11]

There really isn't much to be afraid of Kevin. The carbs. are reletively easy to understand. But the parts have to be almost precision for proper operation. If you have one passage or jet clogged it's, I think, fair to assume that others aren't all that great either. I would go ahead and pull all four. You can leave them all together while you work on them. If you don't have a manual, you should get one. Just take your time. I've been using an electrical degreaser lately. It cleans well and leaves no residue. It's also nice to have a plastic nozzle on the airisol can to stick in those ports. Some guys like to soak the carbs in different solutions. Fortunately, I haven't run into carbs that bad yet. Also, read the tips and stuff on this site for carbs. I started out the same as you a few years ago. Now I'm quite comfortable digging into them.
Matt

[TopCatGr58]

Hey there CRXSi90,

Well, the Pilot jet which supplies for the idle circuit is small and down inside a tube on the bottom side of the carb, not easy to get to or remove even with the carbs off!! The main jet is the larger brass one that will be sticking furthest down from the body, near the middle inbetween the floats! You can unscrew it and inspect it for clogs! Just be careful, there's a small washer on it!

Those brass things are the vacuum slide, main jet needle, and the top of the main jet emulsion tube, and then the butterfly valve as well! I'm stating this, cause there isn't anything in front of the butterfly next to the engine side, and you wouldn't be able to see that area without pulling off the carbs, so I figured you meant on the airbox side in front of the butterfly!

You can try a mixture of Sea Foam, check local boating stores, read the mix directions, it's pretty strong at dissolving gum and stuff!! Might take more than one tankful to see results!? The carbs are not as complicated as they seem, as for taking them apart, cleaning, and putting them back together! Have you read the Carb FAQ's in the tech tips? Nothing beats a thorough disassembly cleaning! Good Luck!
T.C.

[Pat Kelly]

What they said....

[thumperjsa]

If your boots are in bad shape, you should test them by spraying some wd40 or engine start near the boots. If you have a vacuum leak, the engine will start to rev higher. I had one cylinder not firing till i sprayed the engine start and then it would run. Let me for sure know I had a vacuum leak.

[John]

The correct Uni Filter P/N is NU2244. I have been using it for years. If you have to order it, make sure to order the filter oil, and spray filter cleaner at the same time. The O ring that comes with the oil filter can be made to fit better by simply warming it up in a pot of hot water, then hold it in place in the filter cup with some bearing grease. If you have an Auto Zone parts store nearby, they are now selling STP Oil Filters, (with O rings,) for bikes, and they had mine in stock. It was about 1/2 price of the bike shop's cost. and it looks just like the Fram item. Same number of pleats and , the bag with the O ring p/n on it is the Xact same as the Fram, also.
The boots don't always crack all the way through. There seems to be a hard inner liner to these things, and they don't leak. The outside of the boots can be prettied up by using some Plasti Dip tool handle coating. You can also change the color of the boots by buying colored Plasti Dip. I bought mine at a NAPA store. There is an O ring where the boots mate to the head that may be leaking. Check there.

[sidecarKev]

Hey Kevin,

Do you know if one of the pipes is cold all the time or just at idle? I had the exact same problem. The bike would idle but pipe #3 would be cold. I could drive it around, it was ok ovr 4000 rpm and everything but it lacked low end power. I tried sea-foam a couple times, didn't do the trick. These jets can really get clogged and the only way to fix it is to get in there and blast it out. I'm willing to bet you have a clogged pilot jet. The only cure is to rip those carbs out of there and give them a clean. If the carb in question is a carb on the outside you "might" be able to get in there without taking the carbs out. It would probably be just easier to take them out. Come on, you know you want to. You'll learn a lot from doing it.

[CRXSi90]

dragxs11

I've made one motorcycle run better by cleaning the carbs already...Kawasaki csr305...got it from someone in exchange for labor...then a friend who had good intentions of helping me get it running took it for a ride. I figured I'd let him cause he did help a bit. Go figure, he crashed it. So much for that carb work...good for xsperience I guess. Turned out ok...I "sold" it to him....he did labor for the same guy, and the guy paid me instead of him. $350 for me towards the XS which I bought later. I guess I learned that if stuff is clean, it has a chance of working if you adjust it right. I don't really know what a lot of the stuff -exactly-, but I understand most of it. Thanks for the confidence...I got this bike pretty much to gain experience and for a little fun...hopefully it turns out to be both.

TopCatGr58

I'll unscrew and clean the jets...I remember going through that on the above mentioned Kawasaki. The brass things I was refering to were from the experience with that one also. They are like 3 little holes with brass things pushed in around the inside of the carburator air passageway, towards the bottom if I remember correctly. My guess is that gas goes through the jet, through some passages, and out that hole into the flow of air. Am I close to correct?

The cleaner I got was by GumOut, if I remember right. I think I'll run that through after I get this one carb straightened out, and hopefully it'll clean the others some. I'll probably go get some seafoam also...my 140xxx mi. car could probably use some too...it seems like people get good results from it. Then after they are clean in one way or another, I'll attempt to synchronize. I've read some interesting ways, but I think I like the visual method of the mercury synchronizers....I might try to build my own with good ol' h2o.

thumperjsa

I'll give that one a try too...I like the idea of the starting fluid because it doesn't leave any residue behind like wd40 does, but I don't have any around. My list of stuff to get is getting long, isn't it! bah, wd40 probably wouldn't hurt anything anyway.

John

Thanks for the part number. I hope I can find some good bike places locally...I guess I just gotta grab the phone book and start calling, huh? I haven't really gone-a-huntin' for stuff like that, but I do know where the yamaha dealer is . What are the chances that they sell UNI?

I never would have guessed that Auto Zone carried bike stuff too...we don't have AZ around here, but I think I'll try checking with other auto parts stores. How do you think the price at Dennis Kirk is? I hate paying shipping for stuff like that, so I really should look locally.

That is comforting to know that the whole boot doesn't crack like the outside does. Maybe I should take the carbs off and clean if I stand a chance at not mangleing all 4 boots. Then I could remove them and Plasti-Dip them too. We have NAPA around here, I know that! Good to know about the o-rings too...even if I find a leak w/ wd40, there still might be hope if it is right near the head.

Kev

I haven't gotten out to ride it yet...no insurance...yet. I really want to get an air filter and oil change done, and probably the shaft drive oils too before I go for a cruise. I think I'll wait till then for insurance, as crazy as it may be.

The carb in question is on the outside...#4 to be exact. I think I'm going to give this a try, because I practically have the float bowl off. Took some thought, sockets, and phillips bits, but now I can reach all the screws. I do want to tear them off, and maybe I will now that I have a little more conficence in the boot's strength.

If you are ever coming up north again, let me know. I'd like to meet you, but I'm busy a lot of the time...school will be starting for me soon also, but that still leaves evenings and weekends.



Well, for the update...there isn't one...by the time I got home, it was getting dark...maybe tomorrow...

all this talk and so little work from me...I feel like a failure! It is nice that you guys stick around even when I disappoint you time and time again by not getting this stuff done when you give me suggestions. I can't wait till I get the time! ...wait, when is that...when I retire...I haven't even gotten a real job yet...darn, it has just begun.

Kevin

[pgg]

Here's a way to clear the jets and passages without stripping the carbs. Remove airbox. Start motor and hold at 7000 - 8000 revs in neutral. Use hand and seal over each carb intake one after the other. Sucks the dirt clean out.

[CRXSi90]

clever clever...I think I'll go work on it now...I might use that method, but I think I'm still going to pull that bowl just to take a look. Wish me luck!