I’ve had this continuing problem with my ole ‘82 since I got it last fall. When the engine gets nice and warmed up, after say 10-15 minutes of riding, it wants to idle up in the 3000 RPM range instead of down below 1000. It idles fine when I start it up and when the engine’s cold. That high revving, coupled with my clackety-sounding heads is a real attention getter when stopped at traffic lights, but not in a good way. When stopped, I can slow the revs by easing out on the clutch a bit while in gear with the brakes locked, but when I disengage the clutch or drop into neutral, the revs climb back on up. (I do not do this as rule, for obvious reasons.)
I hoped the high revving would subside when I torqued the heads and adjusted the valves, but that didn’t do it. The throttle cables not hanging up and the external linkages on the carbs are also opening and closing OK as the throttle is moved. I have not worked the carbs other than to clean out some junk from old deteriorating fuel lines that was clogging the opening of the float valves. I also have not adjusting the timing, but I am hoping that will help the problem. The bike has about 52000 miles on it and I wouldn’t be surprised if this is its way of telling me it needs a top end job, but that’s still a ways off in the great scheme of things. Anybody familiar with this syndrome and the cause or causes? Timing, carb synch, bad diaphragms and sticky valves are the theories that contemplating right now. Maybe a combination of all the above.
