New to me '78 XS. Caused idle adjustment problem - help me solve it?

[596silverblue]

Apologies for how dumb/elementary this is, but I haven't run across or experienced it before. I bought and trailered a '78 XS11 home yesterday. It was idling at about 2,000. Went to adjust idle speed, and since it was pretty loud, and I was trying not to disturb the neighbors, I turned it off to adjust (I know this was a mistake, now). Started it, and it was idling closer to 3,000. Turned it off, and turned much too far, apparently, because I started her up again and it was idling at 6,000. A littel bit of gas came out one of the overflow tubes (a teaspoon or less?). I turned it off and saw that the idle adjustment screw was way too far out/not touching anything above it. I went the opposite direction, and screwed it down as far as I could, but when I restarted it was still way too high, about the same as last time. Did I disconnect something when I backed it too far out initially? Can this be corrected without removing the tank or carbs? I'm not sure what my next step is, so any suggestions or tips on what's next are appreciated.

[DEEBS11]

You know the bike runs which is good. You should really take the carbs off and clean them then re-install. Lots of info on that here.

[Socer4m]

HI 596, congrats the carbs are 99 percent of the problems on this model.
1. check your oil for gas,,,,push a long stick in the oil filler hole to the oil, pull out and smell,,,,if any gas smell the carbs are into the oil and can really damage engine, do not run the engine if so,,,,and oily gas can cause the high idle.
2. DO THE ADJUSTMENT for idle on the middle bottom front of the carb with the screw, use finger if colder or a long flat screwdrive to adjust , do not use the adjustment by the twist grip until everything else is dialed in
3. if gas smell in oil,,,carbs need to come off and clean thoroughly like Deebs said , takes about an hour, probably a good idea anyway to be safe.
4. also do a carb synch if engine doesnt purr perfectly, info on this site search,,,and check your sparkplugs for gap and color and the correct ones for that year
5. welcome to the land of XS1100
6. keep us informed, lots of knowledgeable members.....
Mike in San Diego and PA.

[Socer4m]

almost forgot,,,,check the throttle cable linkage in the middle front of the carb with a flashlight while turning to see if the cable is not binding and moving freely with the carb plate.....and the throttle should snap back after a quick twist and not bind, if so it needs a good lubing then recheck,,,,,,Mike

[596silverblue]

Hey, thanks for all the information here. I've been riding a long time, but was never mechanically inclined, and am now very rusty - so this is all very helpful.

almost forgot,,,,check the throttle cable linkage in the middle front of the carb with a flashlight while turning to see if the cable is not binding and moving freely with the carb plate.....and the throttle should snap back after a quick twist and not bind, if so it needs a good lubing then recheck,,,,,,Mike

Socerm, can you elaborate just a little? I kind of suspected something with the cable being stuck/kinked - so we're going to get the tank off tomorrow if time allows, and look at that, along with the other stuff. Questions: Is the throttle cable directly above the adjustment screw? Is WD40 ok to lube it, or something more specific to this job? While I'm here - do you guys use NGK plugs?

Thanks again. I'm sure I'll be checking back frequently.

[LAB3]

WD-40 wouldn't be my first choice and other people will tell you to buy the $15 a can cable lube with Zircon encrusted molecules the pretty girl on the Sunday morning Motorhead show is trying to sell you. Personally whenever I get a new old bike I stick with what was used at the time, plain old motor oil. This picture explains it better than words.

[Socer4m]

cable and bracket is right above the idle adjustmnent in the middle front of the carb bank,,,when you yank the tank and or carbs you will see it and it should be free moving with a spring recoil....like LAB3 says any good oil will work for the throttle cable, and it should slide freely in the cable sheathing,,,also you can slide off the throttle handle and lube the cable at the top with some minor dissasembly as most dont and it can bind inside over the years....keep us informed....Mike in San DIego and Pa

[596silverblue]

Just an update - it wasn't the idle adjustment cable. Somehow my throttle cable got kinked/stuck and wasn't returning to "off," or idle position. Wish I'd caught it, but it took my guy like 10 minutes to find it, so an inexpensive learning experience. It's running pretty well, so not gonna dig into the carbs now, but if my fuel treatment isn't magic, likely this winter. Thanks, y'all!

[GalDemSuga]

WD-40 wouldn't be my first choice and other people will tell you to buy the $15 a can cable lube with Zircon encrusted molecules the pretty girl on the Sunday morning Motorhead show is trying to sell you. Personally whenever I get a new old bike I stick with what was used at the time, plain old motor oil. This picture explains it better than words.

Ohhhh I’m doing this for sure😀.