December 21, 2003 {

Over the last couple days, I've noticed that my bike would very intermittently hesitate. I noticed it a few times when cruising in 6th and rolling on the throttle at around 55-70mph. On two different occasions today, my bike went from running like a thoroughbred champion in the twisties to hesitating, "growling" (that's about the only way I can describe the exhaust note) and backfiring.. This was during "very spirited" driving in the twisties, going between heavy throttle and heavy brake frequently. Worst of all, both times it started dogging was going into very sharp curves. Pulling in the clutch, it would idle at 500rpm, very close to stalling. After a couple revs in neutral, the bike seemed to be back to normal and all was right in the world. Riding home I was thinking about the problem and figured that the most likely scenario was that a vacuum slider in one of the carbs was sticking. So I popped the carbs off this afternoon and started taking a look. On all four sliders, there is some up-to-down scoring on the bottom side of the slider and also the corresponding part of the slider bore in the carb. Though some slight scoring should be normal (metal on plastic with only atomized gas as a lubricant for 15 years and 45k miles should lead to some scoring!), I'm thinking that this scoring may be a sign to buy new sliders. While I was in there, I removed the second shims that I added to each needle. I've had absolutely no sign of running lean and, if anything, have been running too rich. Anyways, Here are some pics: Cylinder 2 bore Cylinder 2 slider Cylinder 3 bore Cylinder 3 slider Cylinder 4 slider My camera SUCKS and can't focus worth a damn at anything less than 3 feet away. All in all, Cylinder 1 was pretty clean, cylinders 2 and 4 were moderately scored, and cylinder 3 looks to be the most scored. On all of them, the needle tends to hang downward, no matter how much I try to adjust the needle or the needle plate. It takes finesse to get the needle into the needle holder, which tells me that the needle must not be atomizing fuel too well. Some of the needles were polished like chrome at the spot they normally sit against the needle holder. The scoring still feels pretty smooth to the touch, but I'm thinking that there's enough friction there to keep the sliders from moving progressively up and down their operating range.