2010 Ultra classic. New to me 400 miles ago.
I rode with my half helmet for the first time (Usually use a modular) and I hear this extremely strange tinny sheet metal vibrating noise under hard acceleration. I would swear it is the exhaust heat shields but they are tight. The noise is coming from the front of the engine area. It is not valve train tapping. Nothing else like highway bars, floor boards, etc are loose. Its almost like a mixture of air and sheet metal vibrating. Could it be coming from my air cleaner? Its a Vance & Hines Vo2 intake. I just had the lifters replaced as well as adjustable pushrods. I never heard this noise until I wore my half helmet. I know that fairings (lower and upper) magnify alot of sound. My guesses are noise from the air cleaner or pinging or detonation, although I dont think pinging or detonation would sound like that. I have owned enough Harleys to know that I should expect lots of engine noise, still I would like to hear some opinions. Thanks

 

well, one way to find out is to remove them, just because they are tight and do not rattle does not mean they do not ring under heavy vibration of acceleration.

 

Add some octane booster and see if it doesn’t go away. You’re describing detonation.

 

My latest tank of gas was 93 octane. I will try the octane boost, though. The bike has a Fuel Moto micro tuner but I dont know what tune is in it.

 

Yes I may do that. Also, I think I will remove the lower fairings to see if they are just amplifying the noise.

 

Another thing is that it does not make this sound in neutral when revved up.

 

Whatever it is I have it too on my 93 Heritage Classic. Been chasing it for about 3 months! I hear it less with the windshield off.

 

My bike runs great. I'm not going to worry about it. I put in octane boots with no change. Something is loose and vibrating that's all.

 

Disconnect the blue wire and add two bottles of 104 Octane Booster to bump it up to 208...cross thread points for me!

Disclaimer: don't do that

 

maybe it is rice in disguise?!?