Xs1100 Rebuild thread!

[cywelchjr]

80 carbs don't have the upper t's and other than the earlier ones having the cross passage like the early carbs with the plug are like the 81 carbs with bowls that look like the early carbs. They also have the viton tips like the 81 carbs have, not the metal tips like the 78 and 79 carbs do. But as you said, they still should not leak unless something is wrong, even if something is wrong with the petcocks.

[DGXSER]

You are correct about 80 carbs Cy, but then, who knows what year carbs a PO installed.

[SLKid]

Bike came with three sets of carbs, all different. 3 engines, all roughly the same, 79-80 XS1100s. I picked the best looking engine and Carb set, which were together, and interchanged the needles and jets to same sizes in the "good carbs"
Maybe I can take a pic or two to determine which set I have? If it'll help, it didnt come with the thumb screws on top, and if there were pilot screw caps, they were drilled out by PO.

I'm definately going to clean the carbs and petcocks in the next day or two, reclean needle seats and such and see where I stand after that. I'll be sure to check valve clearance the same day and maybe get some valve shims on order so I can start dialing her in.
Thanks for the thoughts guys! Helps me think sometimes when I get 'second opinions'
-Chris

[natemoen]

If the idle mixture screw is set down in a tower then you have late model carbs. Next thing to look at then is if there is a small passage between the main jet tower and the idle jet tower in the float bowl area. Is there is a passage then you need to have the pilot jet tower capped, either with a screw if it is threaded or with a small rubber plug. If it is not threaded and you have to use plugs the there needs to be a small little nipple in the bottom of the float bowl to help keep that plug from falling out.

Also, what jets do you have in the carbs.

I feel like this post is going to be confusing...

[SLKid]

Idle Mixture screws are indeed set in a tower. Might be headin down today to work on her. I'll report the size of jets when I get back. Double check on the third tower.
Question, if there is a third passage why do I have to cap off the Pilot Jet? Is it another enrichment circuit?
Last question. Gonna need new petcocks anyway, and would prefer to use the On OFF ones. Do the ones on MIKEXS.com fit the XS1100? New petcocks are cheaper than any rebuild kit I've seen!
I'll report back when I get back
-Chris

[jetmechmarty]

Gonna need new petcocks anyway, and would prefer to use the On OFF ones. Do the ones on MIKEXS.com fit the XS1100?

Only the standard matches petcocks with the XS650. If that's the case, then yes.

[DGXSER]

I see you have an 80 Special, might want to add that to your signature line. Helps alot in such matters.

Have you checked on Ebay for rebuild kits? Georgefix typically has them for about $30 or so and very reasonable and speedy shipping. You get everything including the o-ring for the petcock to tank seal, and the valve for the Octy if you still have one. Stock petcocks on the Special have an OFF position.

[fredintoon]

Question, if there is a third passage why do I have to cap off the Pilot Jet? Is it another enrichment circuit?

Hi Chris,
check out where the main & pilot jets thread into the carb body. If there's a slanty hole drilled between the two bores the pilot jet is meant to be fed from the main jet and the pilot jet insertion hole should be plugged or she'll run real rich.
If there ain't no slanty hole both jets feed direct from the float bowl and if the pilot jet is plugged it will be completely starved for gas.
Usually the slanty hole goes with the aluminum diaphragm cover and the separate feed goes with the steel diaphragm cover but beware a possible PO mix'n'match; different year and model carb parts can be swapped around until nothin' will work right.

[SLKid]

Didnt get a chance to go to the Unit today. Maybe tomorrow.
I've been told a few times that this bike is a Standard? The other bike I have is a Special, came with the rounded 79 "special" Tank? The one I'm rebuilding has the curved tank with the indentions, both petcocks have the ON RES and PRI settings.
I'll be sure to check the carbs when I go out. I dont particularity recall a "slanty hole" in the carbs when I cleaned/rebuilt them. But I'll be sure to take a real close look.
As for the Fuel Lines, I do indeed have them on the Bottom Ts. There is no upper T, just the things for the vac line to plug onto. My Gfs Ninja has one of those upper Ts, and the vac ports, so definatly know what youre talkin bout.
Thanks JetMechMarty! I'll probably order two new petcocks and cap off the Vac ports on the carb, and eliminate any vac problems. Wonder if he has valve shims too, and just get it all in one shot.
Just got new ProGrips and clutch and throttle cables in today too. Gonna have to put those on. I'll keep yall updated.
-Chris

[jetmechmarty]

Wonder if he has valve shims too, and just get it all in one shot.

Nope! Mike's XS supports only the XS650. Sometimes the parts are the same and we get lucky.

Marty (in Irving, TX)

[SLKid]

Mk so it looks like I have 3 sets of carbs then. A 79, 80, and a 81.
The 80 is REAL beat up. Missing needles and gunked to hell. The later model does indeed have the Slanty hole in the Pilot jet, thus most likely the reason for my rich mixture, and white smoke. But other than that those carbs are immaculate. Gorgeous carbs. Shame it wont work without modding it by plugging that hole. later model carbs have the 110 mains and 42 pilots btw
So I'm forced to try cleaning and rebuilding the 79 carbs with the upper Ts. Main jet is 137.5 and the pilots have a cap on em. Couldnt read the number on the pilots when i took the caps off for cleaning. The 79 carbs have just about everything, minus a few screws in the caps. I'll use the 80 screws to match it up. Diaphrams look great, minus a little green gunk in carb 2 and 3 these carbs i think will do great when cleaned up. I hope. What say yall on compatability for my engine all cleaned up? Any slanty holes I gotta plug or is she bolt on and go?

Also completed a valve check, BUT.... I seem to have lost my service manual???????? No idea where it is and its REALLY ticking me off I cant find it... Sooo if anyone has a link for a 1980 XS110G service manual I'd be greatly appreciated.
Until then! I have my numbers if someone would like to check for me?

Cyl 1
Intake
Measured: .005 or .127mm
Pad: Y270
Exhaust
Measured: .006 or 152mm
Pad: Y290

Cyl 2
Intake
Measured: .004 or 102mm
Pad: Y280
Exhaust
Measured: .007 or .178mm
Pad: Y290

Cyl 3
Intake
Measured: .005 or .127mm
Pad: 260
Exhaust
Measured: .007 or .178mm
Pad: Y285

Cyl 4
Intake
Measured: .005 or .127mm
Pad: Y265
Exhaust
Measured: .006 or 152mm
Pad: 280

Thanks a million for all yalls support and time!
-Chris Allen

[DGXSER]

Mk so it looks like I have 3 sets of carbs then. A 79, 80, and a 81.
The 80 is REAL beat up. Missing needles and gunked to hell. The later model does indeed have the Slanty hole in the Pilot jet, thus most likely the reason for my rich mixture, and white smoke. But other than that those carbs are immaculate. Gorgeous carbs. Shame it wont work without modding it by plugging that hole. later model carbs have the 110 mains and 42 pilots btw
So I'm forced to try cleaning and rebuilding the 79 carbs with the upper Ts. Main jet is 137.5 and the pilots have a cap on em. Couldnt read the number on the pilots when i took the caps off for cleaning. The 79 carbs have just about everything, minus a few screws in the caps. I'll use the 80 screws to match it up. Diaphrams look great, minus a little green gunk in carb 2 and 3 these carbs i think will do great when cleaned up. I hope. What say yall on compatability for my engine all cleaned up? Any slanty holes I gotta plug or is she bolt on and go?

Chris, First of all, the answer is not to mod the carbs and plug the slanted hole, it is to buy the factory plugs to put in the hole for the pilot jet, letting the slanty hole become the fuel supply to the pilot jet, very similar to the metal screw in plug in the 79 set you have.

I am just a little confused. The 81 carbs seem to be the cleanest, if they are 81, they will no way have the slanted hole between the main jet tunnel and the pilot jet tunnel. If that hole is there, and they have the idle adjustment screw in the front and only one set of Ts for fuel, and the mixture screw on the front of the carbs is down inside the tunnel. Then you have a set of early 80 carbs, I refer to them as bastardized. The jetting is correct for the 81 carbs though, 110 across the board for mains and 42.5 pilot jets. IIRC they should have 185 pilot air jets. Floats should be set at 23 MM +/- .5 MM.

Any year carb set will work just fine on any year XS11 engine, always jet the carbs for the year of the carbs, not the engine they are going on. However, some will say the 80-81 style are easier to tune. Also, putting the 78-79 style with the vent Ts on a later model bike will require opening the holes in the air box or finding an alternate routing for the vent lines.

Also completed a valve check, BUT.... I seem to have lost my service manual???????? No idea where it is and its REALLY ticking me off I cant find it... Sooo if anyone has a link for a 1980 XS110G service manual I'd be greatly appreciated.

Find any post by Catatonic Bug, he has both the Clymers and the FSM hosted on his website, he has a link to it in his signature. The chart is in there, I used it recently myself.

[SLKid]

Thanks DGSXER!!

That was really informative! Thats the kind of info I was looking for on the carbs. I'm not a big fan of "Modding" Stock stuff anyway. Mess with it mess with it and then it doesnt work anymore. And thats no fun for me, and also no fun for the next guy after me.

So where do I get said plugs for my pilot jets? I feel like just adding those would save me a lot of time and hassle. I need to double check and see if the towers are threaded. I can take the plugs from my 79 set and put em in.

I did indeed use CatatonicBugs Manual, and got the new Pad #s. But I wasnt sure if it was 100% correct. According to it all 8 of my pads need to be changed. Bummer. Just hopin I could get a double check and see if my answers are indeed correct.

Thanks for the info!
Off to an interview, Wish me luck!!!!
-Chris Allen

[crazy steve]

As far as your valve adjustment, your intakes are all within spec if you use the later 'tight' clearance. If you want to adjust to the early 'loose' clearance, go down a shim size on each one (ok, you should go down two on cylinder 2). Exhausts, go down two sizes on cylinders 1 and 4, one size on the other two. If you adjust them to the early clearance, you can swap what you have around and only need two shims; a 255 for #3 intake, and a 270 for #4 exhaust...

[SLKid]

I'm always really skeptical about using used Valve Shim Pads. Over time, expanding and contracting, constant contact with the cam lobe, i'm sure if you put some digital calipers on it, it wouldnt be exactly the same as a brand new one. So might as well drop a few bucks and KNOW its right.

I'm looking at
http://www.bikebandit.com/1980-yamah...61?mg=8567&t=1
And trying to determine which pads are ours. The 8.90, 7.48, or 9.48
Love Bike bandits selection. But their shipping is awful..

-Chris