Synced carbs, idle now 3K-4K

[jetmechmarty]

My leaking carbs are fixed. After all that on and off the sync was way out and idle all over the place. I took it to a friends shop. It ran great with the throttle open. We synced it to perfect. I get up the road a way and it's screaming with the throttle closed. The idle adj is off the stop. The throttle cable is loose. All the vacuum hoses and plugs are in place. What is it that won't let me adjust the idle down?

[BA80]

Check all the sync adjustment screws and make sure ALL the carbs are returning to idle position not just #3. Other than that, leaky boots.

Something is hanging up or leaking somewhere.

[jetmechmarty]

Well, since turning some adj screws won't cause a leak, I'll look for the hang-up.

[BA80]

What guages did you use for the sync?

[Joab]

What guages did you use for the sync?

I bet he used the super awesome highly popular homemade gauges

[jetmechmarty]

I went to a bike shop. They're mercury gauges. I don't know what it is other than it's yellow.

With WD-40 I can not find a leak.

It's idling at 3K. Nothing is hung up. If I put pressure on the linkage between 3 & 4, I can get the idle down to 1K. These carbs have new butterfly seals in them. My plug #3 was the whitest one.

[LuckyEddie]

carbs

Marty,

Did he readjust the idle mixture screws? Sounds like you are getting too much juice, keeping it in the midrange.

[jetmechmarty]

Nothing was touched, but the sync screws. Mixtures were left alone. It was real quick, in and out. I popped off the tank and he synced it up. We used only the fuel that was in the bowls. I put it back together and off I went.

[CaptonZap]

I went to a bike shop. They're mercury gauges. I don't know what it is other than it's yellow.

With WD-40 I can not find a leak.

It's idling at 3K. Nothing is hung up. If I put pressure on the linkage between 3 & 4, I can get the idle down to 1K. These carbs have new butterfly seals in them. My plug #3 was the whitest one.

Just out of curiousity, who put in the butterfly seals? Did they center the butterflys after installation, and before tightening the screws?
If they are not centered, they can hang up until they are forced closed, which shifts the shaft sideways, allowing the butterfly to fully close.
The only way I know to check them is to remove the carbs, yeah, I know, and open the butterflys using the cable arm, slowly let the arm down, and look at the seating of the butterflys. I hold the bank up to a light source, hold the slide up, and look at the light slit at the bottom of the bore. They should all be equal. Good luck, CZ

[jetmechmarty]

I farmed out the carburetors. I have CRS, but I think I got it back together last fall. It was running like never before. Then, #2 started flooding the airbox. Yesterday, I replaced the needles & seats, and the main jets. It was running well off idle.

So, do you think I'm going to have to take the butterfly shaft apart on 3 & 4?

[BA80]

The sync is intercoursed......

[jetmechmarty]

How do I UN intercourse the sync?

[BA80]

First, make sure all you did is correct. ( tripple clean theory) Then, get someone who actually knows these bikes to do the sync. Most fuel injected, computer controlled bike techs these days haven't got a clue.

[jetmechmarty]

The shop I go to is an old guy who works on old bikes. He knows the XS11. He turned the sync screws. That's all. I use another guy as well, who works on old bikes as a sideline in his basement. I know better than to let some kid who has never seen a carburetor work on it.

Something is rotten in Denmark, but the carbs aren't dirty. I've been running it. The tank is clean. I'm running the fuel through filters.

The whole bank is up. If I push down on linkage between 3 & 4 it will drop to 1K. This is with idle adjust off of the stop. It shouldn't run at all down there, I would expect.

Greg, I may take it back to Big Steve's Scooter Shop. He can probably get to the bottom of it in a minute.

[BA80]

All I can give you is my advise. No hard feelings if you don't take it. If I was there believe me I would be right there to help figure it out.

Bottom line, either the sync ain't right or there's a vacuum leak. That's going off the information posted. That's fact Marty.

Your saying that everything that can cause that problem is as it should be. Sorry, your wrong about that. One of three things is wrong (1) binding carb cable or linkage, (2) vacuum leak (unlikely in this situation), or the sync isn't right ( most probable from the info supplied).