First, forgive me if this is a noob question..
Just bought an '06 sportster, and it's been riding great except one thing. When i'm holding on the throttle around 55-60 mph, the bike will occasionally act like I let off and rolled on extremely fast. My guess would be the air filter, but i'm not 100% sure, and I would like to avoid messing anything up if it can be avoided.. I've ordered a K&N filter for it for the time being, but haven't received it, and I will be moving up in air cleaners once I can convince myself to buy pipes..

TIA, TheHorse

 

I just had the same type of thing happen with my 77 XLH sportster... Reading through the threads here I found that it was the ignition circuit breaker. I ended replacing all the circuit breakers and fixed a couple connections as well under the seat.

It was a cheap fix and may be your issue as well. But, I'm a new guy and learning as I go. See what others have to say here as well...

Good luck!!