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I would appreciate some help getting my carbs running smooth. I cleaned them and had to drill out the brass plugs to get the pilot screws out. I put them back by lightly seating them and backing out 1 1/4 turns. I presynced the carbs with the bread tie wire. It cranked right up but the idle was running way too fast. I used the master adjustment and got the idle down but when I ride it the rpms creep back up like the throttle is sticking. Does anyone know what a good setting for the pilot screws is on the 80 sg? I haven't tried to sync the carbs yet. I have a set of vacuum gauges to use for that. Any help would be greatly appreciated. Sam
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Sam -
Hi Sizzsam,
Two old favourites for a creeping idle; Either not enough slack (free play) in the the throttle cable, or a vac leak somewhere between the carbs and motor..... Around the boots or the caps where vac gauges plug in is a good bet.
Are you sure that all the vac lines and caps are back on where they should go?
AlanBIf it ain't broke, modify it! -
Thanks Alan. Isn't technology wonderful. I noticed you are from Scotland and I'm in Georgia and we're talking xs1100's. Neat. I'll check that vacuum leak out in the morning. I didn't take the caps off but I have the boots on with the clamps screwed tight but I will recheck them. I looked at the bike too long. Sometimes when I get back to it things kind of fall into place.SamComment
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Most of your problems will probably go away once you've done a good vacuum sync.Ken TalbotComment
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Thanks Ken, I noticed you have an 80 model. How many turns out are your pilot screws? Would that be a variable depending on the size jets used? The PO had jets that were too large so I went back to stock when I cleaned them. It has 4 into 1 exhaust with foam pods.SamComment
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I honestly couldn't tell you how many turns out the pilot screws are on any of our X11 fleet. I believe every engine is different from 30 years of wear, jetting, air filter condition, state of tune, etc, etc.
Start at 1.5 or 2 turns out, it really doesn't matter. Do a proper carb sync with vacuum gauges or mercury sticks. Then, adjust the pilot screws following this procedure . Follow up with a further sync, tweak the pilots again, and have one final look at the sync.
If the carbs were scrupulously clean at the start of all this, you should now be in peak tune and getting every last bit of performance your XS has to offer.
Short cut anything along the way, such as not having a clean air filter element, and all bets are off.Ken TalbotComment
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Thank you Ken for the information. I was a little confused since I haven't done a carburetor sync before. I had information overload and your email put it in perspective. I think I have it right now, correct me if I'm wrong. I have to sync the carbs first using the throttle adjustment screws between the carbs. Once I get all four in sync then I can adjust the pilot screws for each cylinder one at a time and then resync the carbs if needed. I can do that. Thanks a lot.SamComment
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Hi Sizzsam,
You have the right idea with the synch/pilot set; be prepared to run through it all a couple of times to get it spot on. no3 carb is "fixed".... the rest of the carbs get synched to it.
If your bike has a four into one and foam pods, you will almost certainly need bigger than stock jets, and probably the needles lifted a touch.
There is a chart on here somewhere of jetting recommendations to suit mods; try the tech tips (of p'raps one of the clever guys will give us a link?.......) They are a starting point, not a definitive answer, but a whole lot better than stabbing in the dark.
AlanBIf it ain't broke, modify it!Comment
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Thanks Alan for the advice on the jets. I'll see how it runs when I get it all synced. I appreciate all the good help. Now it's time to give it a go.SamComment
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