So I have a '88 upgraded to a '96.......usually I am reading/seeing 3000rpm going 70mph in 5th gear.......today all of a sudden my tach reads 2400rpms going at 70mph....
How did i drop 600 rpm??
Roads are pretty flat in florida, no hills. Is something going on with my engine????? ....engine work was done 3 years ago.
Thnaks

 

70 in 5th gear on your bike is 2964 RPMs- that is an absolute

(unless the clutch is slipping...then the rpms would be higher than 2964)


Check your tach wiring...no sign of misfire?

Mike

 

On my 2000 Road Glide (back when I still had it), a few times I noticed the tach and speedometer didn't "seem right".

As far as I could tell, when the ignition is switched on it would take a moment for the electrics to "initialize". Seems like now and then the tach/speedo didn't "initialize properly" (I think it was because I pressed the start button too soon).

Shutting the engine off and restarting it (and giving the circuits a couple of seconds to initialize) solved it.

 

Same thing was happening to my Roadking. Although it's a 110 the tach would sometimes not match the actual speed that i was going. Sometimes off as much as 1000 rpms. Then check engine light would come on intermittently. Cycle the ignition and it would go away for a while, but always came back. No codes were present. Thanks to the smart advise and explained symptoms by forum members, it turned out to be my voltage regulator. Replaced it and all has been perfect since.