I just drilled mine this afternoon after reading this thread. I thought I might as well. I bought the drill bit last summer and I've just been putting it off. The bit popped through the 1/8th inch of soft metal like nothing at all. I swirled a little cone shaped dremel grinder between fingers to knock off the burrs. On the right side carb I noticed some crud in the groove and on the edge of the diaphragm, which I cleaned up with some alcohol and a cotton swab. Some moisture must have gotten in there. I had no problem getting the rubber diaphragm to lay back in the groove.
The bike started right up. I always take that to be a good sign. The throttle response was quick. We got a record snowfall last night, so I'll have to wait until it melts off before I can go for a test ride. Maybe next week.
