10-15 mpg ????

[samm895]

I just got my XS on the road and I'm getting horrible mileage. It is between 10 and 15 miles per gallon. I am a little heavy on the throttle, but not THAT much. What should I check to get this sorted out? By the way... I now understand why you guys like these bikes so much- they are a blast to ride...stupid fast.

thanks

[mlew]

You have to be blowing black smoke, running way too rich. Hopefully there are no fuel leaks. Getting that bad mileage you are blowing black smoke or leaking it out. Did you do any carb work recently?

[CatatonicBug]

Congrats on getting it running!

A couple things to check on for the MPGs:
Plugs - are they new? If not, might replace them just to be sure.
Fuel/Air mixture (AKA Colortune) - have you adjusted it correctly? Check out the tech tip for how to do it by ear.
Are your carbs clean? Make sure all the jets (fuel AND air) are thoroughly cleaned.
Compression? Make sure you're getting power from all 4 cylinders.

Normal MPG is around 30, +/-5. Some have managed to get over 40 with proper tuning, or using a Dynojet kit.

[tadtl1]

gas in oil?

Hi,

First check your oil for gas in it, its likely your floats are leaking and they could be draining into the oil. Put a long item into the oil, pull it out, try to light the oil with a match, if it lights, its gas, if not, its oil only. Check the air filter and associated for traces of gasoline pouring out. Fuel tends to come out the air jet intakes in the carbs if the floats arent right. I took my intake air filter off completely until I got that solved. If you see gas come out the air jets, tap on the bowls to settle the needles and seats to where they need to be. Also, check for dirt in the needle seat area and the screens above the needle seat. Check to see if the intake needles have ridges worn in them. If so, replace needle and seats completely. The kits from k n l , goeorgefix work great along with a triple clean. Dont ride the bike until youre sure that there is no gas in the oil, if the oil does ignite, it must be changed although someone here lets the gas evaporate thru an open filler hole, but I wouldnt trust that.

[XSokieSPECIAL]

Sam......

Yes, check all that stuff..........also if the bike has been sitting the brakes may be binding up.

Sticky brakes will kill your mileage too..........JAT

[samm895]

Carbs are clean, no black smoke. Cylinder #3 smokes, but I think it is burning oil or has some sort of leak. I have not done the color/ear tune yet, but I probably should. I did have some problems with my floats and carbs were overflowing, but I got that under control so they do not overflow anymore. Could that be another thing to look into? I readjusted them, but that doesn't mean they are right.

[latexeses]

Without going back through all of your posts...Have you done a good sync on the carbs??

[tadtl1]

clean carbs thoroughly

Hi Samm,

If youre not super confident on the floats needles thing being cured, I would be addresssing that first. Its quite simple really. My needle screens were very polluted with sand looking stuff and the seats area had this sandy crust on it that could easily have held the needles open. Also, if the float height isnt perfect , the needles can cock sideways, and cause leaking. If you are running the engine when the floats overflow, you may not actually see the overflow kuzz it willl get sucked into the engine, its only when the engine isnt taking in fuel when the actual overflow will come back out the air jets. I also think that being on the side stand may contribute to odd things happening with the floats since they put things at an angle. Put the bike on the centerstand if you can until you are sure. Also, whats up with the octy, and the petcocks. I got rid of the octy, since I dont mind shutting off the fuel when stopped. I have a continuously leaking petcock, in other words, even when shut off, it is allowing fuel thru. I put in an aftermarket five bux shut off in line with that petcock. Be sure to put inline filters in the lines, ten bux, such that any rust from the tank cant get thru. All of the things mentioned by everyone so far are good ideas to look at, dragging brakes would not have really been on my radar screen but of course could cause such a mileage fiasco. Good luck and let us all know what you find in the end please.

[samm895]

My carbs were overflowing so I adjusted the float settings so they do not leak anymore. They still might be getting too much fuel though. My petcocks are 3 settings: prime, on, and reserve. Get best running results on prime, so thats probably why mileage sucks. The vacuum line on left side of bike blows back every once in a while and I don't know what that means. Bike is always really powerful, but sometimes (I guess when its running correctly) it is ridiculous how fast it is. I will try to sync the carbs and check everything else out. 3 of my mixture screws are missing the tips-tips are out of carbs. I bought some new screws from carbkitcapitol.com but they do not fit, might fit '80 or newer carbs. Thanks for all the input and I will let you know when I figure what the culprit is.

[CatatonicBug]

If you're missing the tips of the screws, THAT'S your problem! Don't even TRY to tune anything until you have the proper screws in there. They are undoubtedly allowing too much fuel into the cylinders, since the tips aren't there to get in the way.

[cywelchjr]

If you're missing the tips of the screws, THAT'S your problem! Don't even TRY to tune anything until you have the proper screws in there. They are undoubtedly allowing too much fuel into the cylinders, since the tips aren't there to get in the way.

+1 on the tips. It's one thing to have the bigger hole with new screws, but you need those tips to be able to tune the idle circuit, which BTW affects all running ranges, and that could certainly kill the gas mileage. I don't ride like an old lady, I like to be pretty brisk getting up to my driving speed, but I get about 27 - 30 around town, and around 37 on the road.

[samm895]

Thanks, where can I get screws for '79 standard? The ones I got from carbkitcapitol.com have a spring, washer, and rubber seal. Mine just have a spring. New ones are threaded all the way to top, while mine have a screw head up there. Threads are smaller on my screws than on new screws. I saw something on putting screws in a drill and trying to run then on really fine grit sand paper, but I can see myself screwing that up. Yamaha says $22 each- so they can go..... So if anybody has a few extras or knows where to get them let me know.

thanks

[CatatonicBug]

Send a note to e-bay seller georgefix. He's a well-known, respected seller of XS carb parts (among other things). They're still going to be a little pricey, but more like $12 each, IIRC, and you can be sure they will fit.

[XSokieSPECIAL]

Check here bro'

http://www.carbkitscapital.com/carb_...a&model=XS1100

[CatatonicBug]

http://www.carbkitscapital.com/carb_...a&model=XS1100

It doesn't look like they sell the right ones. Even though they SAY it fits ALL XS11's, this is the only one they sell, and it's for the later model carbs.



The one he wants is the one from this kit, for the earlier carbs: