Pinging noise in my 07 Ultra

I have heard some pinging/tingling noise on my ultra the last few times i've had it out. First two times i heard it was down in the mountains and thought it may be altitude related but it does it here in my local area and im only 650 foot above sea level here. Not much chance of an altitude issue huh! Anyway I hear it when in third or fourth gear and when its running around 3700 to maybe 4200 RPM's. Hard to explain but id say its like a ping or high pitched tingle. The local HD shop said it was pre-ignition and not to worry about it. Also they said I may have been running it a little too easy. I had been keeping the RPMs between 2000 and 3000 for the most part. The bike has 3400 mile on it now. There were five bikes together in the mountains and none of the others heard theirs tingle and we all gased up pretty much at the same times. Dont think it was a problem with the fuel quality or others would have heard that same sound. Is the pre-ignition a logical diagnosis or should I take it elsewhere? Oh yea, I've picked up the RPM's and keeping it up around 2500 cruisin and around 3500-4000 just runnin through the gears. Stilll pings! Not all the time but frequently.

RDean

Hi RDean

You might try High test gas. If its preignition it should stop the ping. If you tend to lug a motor it will carbon up causing the compression to be a little higher. That will amplify the problem. Its worth a try. Have a nice day Ole Ted

Thanks guys! I've been running high test gas (93 when available) from the gitgo. I'll try the additive and see if that cures the ping. Chuck you think I should have the map/ecm checked even if the ping goes away after using the additive in the fuel?
Thanks
RDean