Idle Problem

Damn. She was running so well yesterday, but today she's gone bonkers. As soon as I started her up she had trouble idling. Figured she'd be a little better once she warmed up, but no such luck. Spent fifteen minutes in a deli parking lot messing with the idle and mixture screws to no avail. She would either die or jump up to 2,000 or 3,000 rpm on her own. The random jumps and drops in idle made me think air leak, but I also noticed the blinkers weren't blinking correctly. They were blinking irregularly and too fast, even though all the bulbs were working. So maybe it's electrical?

I'm going to go spray some WD-40 around looking for an air leak, and then poke around with the multi-meter. I feel sorry for Dave's neighbors who are going to have to listen to my bike some more.

Update

Well, it seems to be a leak in the boot between the left carb and the head intake. If I pull on just the left throttle it doesn't increase the RPMs, it just makes a loud thwup-thwup-thwup. After I let go of the throttle the RPMs increase slightly for a few seconds. While it doesn't backfire, I'm assuming that the thwup-thwup-thwuping is the mixture too rich, and the momentary increase in RPMs is the mixture passing through a proper ratio of air to fuel on its way back down to being too lean due to the air leak.

Spraying DW-40 on the boot doesn't do anything at first, but after ten or fifteen seconds the RPMs shoot up. It took a few tries for me to put two and two together, as I expected the DW-40 to act more quickly.

I wonder how this happened between yesterday and today. The only things I can think of are that the plastic cover was pressing on the carb and putting pressure on the boot. Or maybe I tightened the hose clamp too far. Now to find out how much a new boot is, and if there's a temporary fix that'll get me back to SF.

Re-Update

Rode over to Auto Zone to get some liquid gasket to see about sealing up possible air leaks. Also picked up some fuel line to replace the old ones as they've started to leak. She had problems accelerating/maintaining speed the whole way over. Came out of Auto Zone to find fuel leaking from the left air filter. That about drove me bonkers, but then I realized that the overflow hose passed above the air filter, so it wasn't that the overflow was clogged. Hammered on the bowl to loosen the float and rode to get a bite to eat. After eating I came out to find that she was running well again.

I'm not so sure that the problem was an air leak any more. Maybe it was that she was running too rich. Still not sure why she would just start running well again. Gonna see how she's doing tomorrow. I'm actually hoping the problem comes back. I'd like to get to the bottom of it rather than just be glad it disappeared randomly.