Engine Stumbles, Tach Spikes
So, I'm cruising at 60MPH on a cool spring evening in Colorado (Denver altitude, not in the mountains) on my 1990 stock 750 (with about 23,000mi.), and the engine starts to momentarily and intermittently cut out in a manner very similar to the POOGS problem. However, the engine did not die, and out of the corner of my eye I notice that the tach was momentarily spiking UP in RPMs as the engine seemed to hesitate (as much as 1000-1500 on the dial). The problem has persisted now into a second day, and it seems to happen at all speeds and in all gears. I cannot determine yet if it happens with the bike just at idle.
A forum search led to one thread (#19054) which suggested a faulty/loose battery ground connection. I immediately checked that, but it does not "seem" to be the issue. The very last thing I did as far as work on the bike was to synchronize the carbs, but I cannot imagine this would be the cause of the problem.
I realize the tach is electrically (not mechanically) driven so I am posting this in the Electrical Section, but since I am at best just an amateur mechanic, I seems it could be any number of things. Does anyone have other suggestions for a strategy to find out what the likely source problem is?
Thanks for any help you can offer.