XS1100H Carb Sync Issue

[DGXSER]

For the uninitiated, on this process, start the bench sync with adjusting the idle screw so no 3 carb butterfly is set to the prescribed opening, bread tie, tiny drill bit, or fuel hole as shown in the link.

Then use the synch screw between 3 and 4 to get 4 to the same opening. Now use the sync screw between 2 and 3 to adjust 2 to the same opening, then finally the sync screw between 1 and 2 to get 1 to the same setting.

The key to that sequence being that the sync screw between 2 and 3 really is adjusting the butterfly on 2 to match 3. No 1 butterfly just comes along for the ride when you adjust the 2-3 screw.

[Yard Dogg]

I think you have an issue with 1 or 2 carb. You're syncing is just fine. You may have a plugged jet, plugged emulsion tube, high or low fuel level, maybe an idle screw hole plugged or a little damaged, damaged diaphram, etc.... Point is, when you start to close the throttle flaps on 1 &2, the vacuum goes up on those 2, then the mixture is too rich. That's why you can't bring the idle back down.

[MPittma100]

Bench Sync

Thanks Marty and trbig (Tod) for the info on the carb sync. Looks easy enough. Will be a little while until I get to it. Got top finish up our racing season first, but am looking forward to getting the bike exactly correct.

See you guys at the rally.

MP

[MPittma100]

Sync Issue Solved

Got to work on the sync issue today. Removed the carbs and inspected to see if a bench sync was in order. All looked really close. The only thing that I noticed wrong was that the adjusting screw lever between 2&3 (the one with the throttle cable bracket) was bent/cocked.

I would guess that a previous R&R got this bracket up against the oil transfer tube bolt at the head causing the bend.

However it happened, I straightened it and reinstalled them. As a result, unlike before, the main idle screw could now be turned to where the engine would shut off. And the sync on the Carbtune came right in like they are supposed to - all columns even. Runs XSWEET! This one is coming to the Rally.

MP

[DGXSER]

Nice work finding and resolving your issue!!