Yet Another carb issue!

[Keithh]

Hopefully one of the XS guru's out there can help sort this one out! I rebuilt the carbs and got the bike (79 XS11 Standard) up and running. I sync'd the carbs and the engine seemed to be running great. Started quicky, settled into a nice idle, crisp throttle response. However, it did note the number three carb leaking through the vent when shut off which pointed to a stuck float needle valve and a leaking petcock. Rebuilt the petcocks, pulled the carbs and gave the leaking one a good once over. Assembled all and no leaks - problem solved. Not quite. The bike now starts quickly, but goes to a very high idle (4000!!) with the choke on. Better at half choke. once warmed up a little, it idles, but a little rough and doesn't want to transition off idle to about 2000 RPM or so, then clears out and accelerates cleanly. I tried adjusting the mixture screws in both directions, and it improved some, but now when the throttle is blipped, it tends to stay at around 2000 RPM rather then settle back to 1100 RPM. Occasionally it will, but really hit or miss. No amount of adjusting appears to make it happy. I suspected an air leak, but could find anything and the WD40 test revealed no apparent issue. I still suspect a lean condition, but I'm at a loss given how well it had run before. I am getting way too good at pulling the carbs off! Any thoughts greatly appreciated!

Regards

Keith

[79XS11F]

Re-sync them at full operating temperature. Anytime you re-clean, fix a leak or re & re the carbs they should be re-synced. Do it while the bike is hot for best results. Check your plugs as well. If there was a rich mix before the leak was corrected one of 2 of them may be blackened. OH and 4K on full chock is the correct full chock RPM.
Rob

[Keithh]

Thanks - I'll give it a shot!