High idle after sync, + rear brake pad

I have a few questions about a sync I can't get quite right, but first a story.

I took my XJ650 to get new tires installed. The shop couldn't get the rear wheel off, claiming it was seized to the axle. They refused to try any more, so I had to take it to a second shop. This guy also had a hell of a time, but had a little more gumption than the first shop. The brake plate (?) was seized to the wheel, and it took a couple people and an overnight soak. He said in 20 years it was the most seized wheel he'd ever seen! Anyway I'm riding on 2 new tires finally and feeling better for it.

The other thing that came out of that was that the rear brake pad was 90% worn through and the rear brake pedal was bent inward so that it wasn't stopping against the case. Is there a way to bend the pedal out so I don't have to buy a new one? Haven't looked into it yet, but I'm assuming the brake pad is relatively easy to replace by myself.

The real question I have though is about my carb sync. I have thoroughly cleaned my carbs (using the guide here--only took about 5 times to get it right!), done a bench sync, and synced using a poor man's tool made out of a couple of glass starbucks bottles. I've tried it a couple times and keep running into the same issue. Before I pull the carbs off to start over, I wanted to ask what I'm doing wrong.

When I do the bench sync, I used a paper clip at first, later a strip of 3x5 card and *really* got it as perfect as I could. (Fuel levels are all checked, and throttle shaft seals replaced.) When I start the sync, I do 1+2 until they're level, 3+4, then 2+3. The sync is perfectly level after this. The main problem is that when the bike is cold it idles at around 1100, but after getting warmed up, the idle climbs to about 2500 (close to 3000 after highway riding). It's steady at this level, and doesn't "hunt." My idle screw is all the way out, and I've adjust the mixture screws with a color tune.

Do I need to start over with a bench sync, reset the mixture screws, and give it another shot, or can I just turn the idle screw in a few turns and adjust the 2+3 sync screw to balance it out? Not opposed to doing it again, but I've tried a couple times and keep winding up in the same place with a steady, but high idle. Any thoughts before I keep beating my head against the wall?

 

Ummm--- turn the idle down once the bike's truly warm?

Your valves are in spec, I hope?

As for the brake; take the pedal off, clamp it (wrapped in cardboard so you don't gouge it) in a vise, and bend it back.

And replace the shoes, fercryinoutloud.

 

Yeah, definitely replacing the shoes -- it just surprised me since I got the bike at 5k and have only put 1k on myself. Valves are in spec, I adjusted them about 6 months ago.

Problem is that I can't turn the idle down any more -- the screw is all the way out. My question is whether I can tweak the middle sync screw so that I can fine tune the idle. If so, do I need to tighten or loosen that middle sync screw?

Sorry if it's a dumb question, I've just gotten myself into this situation a couple times in a row and thought I'd ask before I screw it up further.

 

Ahh gotcha.

You may have "bench sync'ed yourself out of adjustment."

If the idle rod is backed out too far when you begin doing a bench sync, you can end up with the carbs not all being able to have their butterflies close fully.

The final check when doing a bench sync is to make sure that when you back the idle off, all 4 close fully.

Adjusting the 2/3 screw won't help #4. I can't tell you which way to turn the screw; it would depend on which direction it's off/needs to go.

Where are your pilots set?

 

I was afraid of that. I have a hell of a time finding things on this forum and I'm looking for the bench sync guide I used, but if memory serves, I thought the final check was to adjust the idle screw so just a "sliver of light" could be seen underneath the butterflies. Maybe the idle screw was too far out at that point. How can I figure out which way to turn that middle sync screw to "shut" the valves? I was thinking I could turn the idle screw in (opening the valves more), then adjust the middle sync screw back until they shut--giving me fine idle control again. Does this make any sense to try?

What do you mean about my pilots? The jets? Everything is stock - recently replaced the pilot jets that were pitted.

Hard to say where my mixture screws are. When I did the bench sync I bottomed them out then backed them out an equal distance -- I want to say 1.5 turns? However after getting my vacuum sync level, I used a colortune and adjusted each one. Think I should reset these to the same level before attempting the sync again?

Or back to the drawing board? Not that I don't love pulling my carbs off for the umpteenth time, but I'd like to avoid it if possible.

 

Welll... the mixture screws (ColorTuning) can and will affect the sync.

You did a bench sync, then a running vac sync, then used the ColorTune?

Did you then GO BACK and do another running vac sync? If not, the problem may simply be that ColorTuning threw your sync off. If you got the mixture tuning right (using the ColorTune) then I'd start by "tidying up" the vacuum sync.

You are blocking YICS for this; and your float levels were accurately wet-set, right?

 

Ah, I did NOT go back and do a running sync after the color tune.

I don't believe I have a YICS port, but clearly I'm new to this. I have the RJ silver Seca (not the red one). Float levels ARE accurately wet-set (took a couple times but I'm sure they're right on now).

I can do the running sync, but still can't reduce the idle. Before I do the sync, can I close the sync screws an equal amount and tune it with the vacuum gauge?

 

Oh ok ok ok. Sorry. Add an "R" to your bike in your signature; I assumed Maxim. The '82 Maxims had YICS motors; no, you won't have to worry about YICS. If you're a fellow 650 Seca owner, it's a pre-YICS motor.

Here's the thing: If the butterflies can't all close, it won't idle right or come down. It also won't idle down if it's very far out of sync; one carb runs high, and it starts to pull the motor up so the others join in and...

So the more you fiddle with it; especially "blindly" (without gauges on it) the further you're going to get from a good sync.

I'd honestly go back to square one and be sure all 4 butterflies are fully closed when the knob is backed out all the way. Leave the pilots where they are since you already did your ColorTuning; then once you've got a sync touch them (and then the sync) up again.

 

Okay, thanks for the help, fitz! Glad to know it won't be a waste of time.