Good Morning All. I've got over 20k miles on my Heritage. About 5-6k ago, I started to notice the throttle didn't feel very smooth. I attempted to lube w WD-40 and it improved somewhat for a short period. It's pretty bad now and in a quiet room, you can actually hear the stickiness. Talking to the dealer (it's still under warranty), this is known to happen with bikes that are ridden a lot. He also said to not lube the twist grip sensor, when they wear and get sticky, they need to be replaced. They have the part in stock and they'll be replacing it tomorrow. I'll keep you posted.

 

I had my throttle start to stick, i just had to loosen the controls and move them in a hair. maybe this happened to you? here is the youtube link.
sticky throttle

It was a quick easy fix.

 

I disassembled the switch cover and removed the grip. I had the old grip (left over from the grip swap) and cut the grip down so that the only thing left was the part of the grip that connected with the grip sensor. It still creaked loud enough for my wife to hear across the quiet garage. Interesting video though.

 

I got the bike back following the throttle grip sensor replacement. I'd forgotten how smooth the throttle can be. Before I took the bike to the dealer, I had to remove my Powervision tune and put the stock tune back in. After I got the bike back home, I put my tune back in. Riding my tune back to back with the factory tune reminded me of just how much difference there was. With the stock tune, the throttle response wasn't as sharp and revving up through the gears you could feel slight flat spots. I had a Fuelmoto tune that I'd had autotuned a number of times to get it dialed in.

 

In the future, I wouldn't use WD40. It's a short term fix. The WD40 will stay wet and end up collecting more junk and make the problem even worse. You want a dry lube like a graphite, garage door, etc.