I have a 2006, Electra Glide Ultra Classic, I'm getting a metallic sounding rattle when I accelerate. I notice it when I'm going fast and throttle down hard. My bike has about 13,000 miles. Help a brutha out!

 

Spark knock
loose heat shield on exhaust
cam chain
primary chain

need to figure out a little better description.

 

Check your slip on bracket rubber bushing

 

I've had the gas cap make some crazy sounds at certain vibrations on my '06.

 

Noises are something that typically can't be sussed out on the World Wide Web...they can be frustrating, for certain, but there's no way that we can hear what you can hear...

 

I 2nd spark knock.. my cousins 08 has been doing it for years and his is definitely spark knock


you don't say if you have changed exhaust/AC or both BUT
get some good premium 93 octane or some octane boost and see if it helps

 

Ill try switching out the plugs! Thank you

 

How fast and what gear are you in when you put the hammer down?

 

Somethings loose, check all your bolts and clamp nuts.