Fixing '79 XS11

[Flavj]

Hello all, I am new to the site and to the XS11 motorcycle. I am currently working on my bike and am having some trouble. I bought the bike from a friend of mine and he had the engine apart. He took the head to get the valves ground and reseated. I put the bike back together following my clymer book to the last detail. I am not familiar with motorcycles, more into older trucks. I took the bike to get the valves shimmed and the carbs synced, the guy called me saying the bike was smoking out the exhaust, and oil was dripping from the muffler coupling. I brought the bike home and hooked the gas lines up to the tank, turned on the pet cocks and gas is running from the air filter box. After running the bike for awhile off the gas that was left in the float bowls and lines the smoking stops and the bike levels out on idle. If the bike is left with the pet cocks on it obviously floods and spits and sputters. I think that the excess gas is running through the exhaust and taking any of the oil residue off the pipes and making it appear to smoke. I offset all the piston rings, and the head was taken to a reputable shop. If anyone has any suggestions for me they would be much appreciated. I am going to go through the gas lines and make sure they were all hooked up properly. If anyone could maybe send me a pic of how theirs are hooked up that would be good.

Weather is getting to nice to not be riding. Thanks for any help.

[dbeardslee]

Sounds like a stuck float or crud in your fuel valves. First thing to do is try rapping on the float bowls with the back of a screwdriver. Lots of times that will free a stuck float. If it keeps doing it, it's time to pull the carbs and check the fuel valves. You'll also want to check your oil for gas contamination. If the gas is running into the airbox, there's a good probability that it's also going the other way - into the cylinders, past the rings, and into your oil. Running a motor with gas thinned oil can result in bearing failure. Put a stick into the oil through the fill hole, repair to a safe distance and try to light the stick. If it lights easily you've got gas in the oil and you need to change it.

[Rickrod3]

Which 79 do you have?

Welcome to the site.
Which bike do you have the standard or the Special.
XS1100F would be the standard
XS1100SF would be the special

I own a Standard and as I understand the Specials have a different gas piping arangement.

Once you post the model you have (It's best to be put in your signature) others with more experiance than myself can help you.

Rick

[DGXSER]

Yep, Doug (Dbeardslee) hit the nail on the head. When gas flows out the airbox, is it because one of the float needle valves in the carb bowls is not sealing off when it reaches the appropriate level.

You did not say if you had anyone clean up the carbs. These carbs are VERY finiky about being clean, especailly that float needle valve.

Being a 79, you also want to make sure that the upper Ts are ran to the air box unobstructed or are open to the air. These are vents to the float bowls. Only the lower Ts get fuel lines ran to them.

[Larrym]

Fuel Flowing: Uncontrolled

Flavj,

From what you've provided I'd say the fuel is leaking (scratch that..flowing uncontrolled as in "Noah's arc" flooding...yeah. I'll go with that.) into the cylinder and washing everything in gas. Then continuing through the exhaust.

Your experience with trucks/auto will transfer just fine to the XS. If you've ever pulled off a carb then here's a real treat: 4 of them. Lot's of pics and "how-to's" in the tech tip section so if there ever were a time when the "RIF" program (Reading is Fun ) we had in grade school pays off...it's here. Specially in the carb section where knowing before ya go can prevent you from making "newbie" mistakes like breaking off a float post when you take things apart.

Do what you gotta do and then rattle our cages with anything that concerns you.

BTW: I've got a 79 special and so the fuel line routing is different or I woulda sent a pic.

[ross]

hey there noob...

....just kidding there flavj.....all of us were once new to the site and in search of information...just like you are now.....thats how this place became what it is..you will be able to find just about any information you could possibly need to repair your bike and get her road ready.....first off...finish off your profile and let us know where you are.....your next door neighbor may be a member.....extra eyes and ears can help diagnose the problem....as far as your problem the the fuel management issue.....it sounds like these might be your problem.....


also it could be your petcocks on the tank......i went and installed manual shut-offs to make sure the gas is off when i am....


just be ready to due surgery if need be....


.....trust me (us!)....we can get you through the problems....also you might notice that pictures are worth a thousand words.....

...here is a link to when i did the carbs last year....
http://www.xs11.com/forum/showthread.php?t=17116

....may not be the best but has lots of photos and explanations...btw, if ya need parts, ask...we just might have some laying around u can get for cheap (postage).....
....help and info are here for the asking......until later....ride hard, ride safe....ross

[Flavj]

Thanks for all the input so far. I have already taken the carbs apart and cleaned them, and put new kits back in. The guy that I took the bike to synced the carbs for me. I only did one carb at a time as to keep from mixing up parts. Again following the Clymer book on anything that I was not sure on. My pet cocks on the tank let gas past all the time when in the on or res position. I was reading in my book that gas should only come through them when there is vacuum from the engine. There is a manifold that the gas lines go into, and then the vacuum line from there goes onto the carb boot for the #2 piston. Is the fuel tank supposed to be sealed to prevent gas from passing when the pet cocks are on/res? Is that all my problem is, is that the pet cocks are not shutting off properly?

To be a little more clear the bike was having the same problems when it was purchased by my friend. The bike ran rough and smoked. It was bought from a car mechanic. He thougth that the bike needed head work done to it. The bike had the head taken off sent to a shop for valve work. Bike only has 22k original km on it. The pots were taken off and pistons, cylinder walls and rings were all inspected. New complete gasket kit was installed, rings rotated opposite eachother and pots put back on. New head gasket and head reinstalled. Torque pattern done as per Clymer specs (with snap-on torque wrench). Carbs were off the bike and completly disassambled and new complete carb kits put in. Carbs were synced by someone else(person was recommended to me). Now when putting the gas lines back on the bike and turning the pet cock to the on position the gas pours out the filter box. Reading I found gas is only supposed to come out of the lines when a vaccum is made from the line pulling back the diaphragm. Bike smokes only if the pet cock is left open. If running off the gas that is left in the float bowls the bike has lots of power and runs smooth. After leaving it idle though it starts to climb rpm and giving it throttle does not slow it down.

Any other questions about what was done to the bike or any other input would be much valued

[mro]

Even when the vacuum fuel shut off (specials have what we call the octopus , standards have vacuumed actuated petcocks) fails you should not have fuel leaking from the carbs. The float needle valves are leaking.

Check inside the fuel tank for rust or other debres. Takes only a very small piece of $hit to stick open a needle valve. The manual should have a diagram for the fuel line routeing and I'd check to be sure it's right.

mro
BTW, welcome to CH 11
BTW2, your going to have to take the carbs off to get em cleaned ... agin

[mro]

Btw3

Kits are available to rebuild the petcocks and the specials diaparam.

mro

Octopie





Standard petcock



79 carbs when done (by me )

[TopCatGr58]

Hey Flavj,

As has been suggested, a trip back into the carbs is necessary, but only to clear out the inlets, the float needle seats and such, so complete disassembly isn't required.

Then INLINE FUEL FILTERS are a must, but with the Octopus, you have a little dilemna...because you have 2 fuel lines for each petcock. One is the PRIME function...bypasses the Octy, direct to the carbs, the other is the RUN position...goes THRU the octy. With the Octy, not much room in there to put them AFTER the Octy between it and the carbs!? This is partly why many folks $h!tcan their Octy, and either cap off the Prime from petcock ports, or run a "T"/"Y" type connector from petcocks, then have 1 line to each pair of carbs, and it's easier to put an INLINE filter on that line as you loop it around/under the intake ducts. Just remember to turn OFF the petcocks when stopped for a while to take stress off of the carbs float needles, but IF they are doing their job they will NOT leak when the petcocks are left ON! BTW, the petcock function is where the handle points/covers the function on the faceplate.

Also, did you test the floats to make sure that they floated, didn't have small pinholes in them, fluid in them, etc.!? Putting them into almost boiling water, using a tool to submerge them into the water and check for bubbles leaking from them=LEAK!!

Also, there is info about a substitute float needle/seat combo from a Virago that uses the VITON/Rubber tipped needles, more forgiving and better sealing than the metal to metal of the old OEM style...IMHO...YMMV!

T.C.

[ross]

my setup....

hey there flavj....agree with all the advice above.....carbs must be cleaned, cleaned, and then cleaned again.....and you still might have 2 more cleanings before you get all the sh*t out......to do it yourself is quite the experience and the advice is here for the asking.....also in my posting i show how to set the float levels so that fuel is not dumping out.......would check float heights and see whatzup....couple of photos of what ya can do.....
fuel filters and shut offs....


checking the float levels with gas in the bowls.....


....also, look at how to colortune and sync your own carbs.....trust no one that says "yea, i know how to do that!"....(read my signature below about others wrenchin'!)......to do it yourself is "religious".....trust me, you will be addicted and soon you'll be doing the second gear fix......good luck...ride hard, ride safe...ross

[mro]

INLINE FUEL FILTERS are a must

This is partly why many folks $h!tcan their Octy,

Umm ... not to be contrary, OK I am , but if you have a good rust free and clean fuel tank you do not need in-line filters as the petcock filters will suffice. None of my specials have extra filters and the octopi works just fine (kits available to rebuild em). On standards I do use in-lines filters even tho I have good tanks just because it’s pretty easy to do.
I sorta like the OEM stuff. I even polished the aluminum diaphragm on the octy for the last SF I fixed up. (I wonder if Tod will read this )

mro
BTW, I did use a tank liner on one special as it had a little rust beginning and that would have eventually been a problem.

[DGXSER]

I agree about the filters MRO. On Thunderstruck, the tank is in good shape and I have not put inline filters in it. On Banshee, the tank needed a liner for rust through holes after I did electrolysis on the tank. Even then I got crap in the float valves so I added filters. Not a problem since.

As to the Octy, even when I rebuilt it it still did not work right and got on my nerves entirely when I was trying to synch and tune. So it is somewhere in the woods behind my house now. +1 for an octy free world!!

Also, when checking for float valve function, with the carbs upside down on the bench, before you put the float bowls back on, put some fuel to the lines and just blip the floats till a small amount of fuel comes out. Clean it up with towels and dry it with compressed air, but leave the fuel turned on to the valves and walk away. Go make a sandwich and eat it, then go back and see if any fuel has leaked past the float needle valves. Should be none.

Now, put the bowls on, then turn them upside down and try to blow air into the fuel lines, none should go through, turn the carb upside right and you should be able to blow into them. then your ready to mount them on the bike.

[Cleansoul]

Hose number 2 on the Diaphragm asy

Where does goes the hose number2 on the diaphragm asy as show on the picture bellow, if it goes to carb holder #2 where goes the breather on carb number #2?
thank you.

[TopCatGr58]

Hey there Clean Soul,

The Octy #2 hose goes to the Intake Boot port. The port on the #2 carb BODY connects to the hose that goes to the vac. adv. pot inside the left side timing case cover. The UPPER "T" fittings/hoses are vent hoses, and need to go to the ports/nipples on the AIR BOX. Hope this helps?

T.C.