Why is it that my bike seems to run smooth as silk on some days and a little rough on other days. I have a stock 2010 RKC. On rougher days I can hear it in the exhaust note. It's noticeably louder(almost like an aftermarket exhaust) and the motor seems to be working harder. on good days, acceleration is smooth, even, and brisk and the exhaust note is very quiet. I do plan to upgrade to a better/louder exhaust but this is something that I'm noticing while it's still stock. I always use the same gas(shell) and the weather has been consistently hot/humid here in Ga so I don't think thats a factor. Any Idea's?

 

Bad gas. If its temperamental on the same tank of gas, that's a different story. Something is wrong.

 

I kow this probably sounds silly. While riding My ultra, I noticed that the wind direction has a lot to do with handling, power (while riding into the wind) and engine noise,seems louder at times. When I change direction, these symptoms go away. The same things have happened on previous bikes. I have even experienced this in car's. Here in El Paso the wind is something that one has to live with.

 

Humidity, air temp and barometric pressure.
Ever notice riding on cool nights how much better it runs?

 

Heat and humidity play a big roll in how these engines run and idle...Cooler the better for making power!...All Harley's are more temperamental than a Woman!!

 

Yep......

 

Alcohol has an effect.