Motorcycle Repair: RK Noisy Accelerating when hot, rattle sound, two different ways

Question
I have a 2005 Road King Classic EFI - all stock.  When the weather gets 90F+ and I'm either in city traffic or a long ride and the engine is good and hot, I start getting a gurging rattle sound from the engine when I accelerate, or anytime there is extra drag on the bike (rolling hills, two-up, etc.) It's almost like the engine is chugging at too low a gear, but my RPMs have to be high enough (45-50 mph in 4th gear). Sometimes I can even hear it when I'm at 55-60 mph in 5th gear on the highway. If I back off the throttle the noise goes away. I've thought maybe bad gas, but I'm using 93 octane and this has been farily consistant over the last 2 summers.  This doesn't sound like a loose part rattle on the outside of the engine. I've checked the spark plugs and they look fine and gapped correctly.  I've checked the air filter and it's ok.  Fluids have appeared normal.  I'm wondering if it is running too lean (even though it is an EFI system) or some other EFI issue.  Thanks for your input.

Answer
It sounds like your bike is getting hot and pinging. The pinging is pre-ignition from the heat. There are two different ways you can go. You can either have the EFI remapped, which will richen it and make it run cooler or add a oil cooler.
Good luck and happy riding
Mike