I have a 2021 RGL, 5K miles. I have noticed if I stop for a short time (couple of minutes or less) when I try to start, it sounds like it backfires and releases the starter and I have to try again. I hear a sound like a backfire knock, but not really sure what it is doing. I am thinking the engine is hot and ignites the air/fuel mixture when it compresses but before the spark. Any other ideas?

 

Stock 114, or messed around with?

 

Never had an issue like that on any of my M8s. That said, I've had compensator issues on a couple of my old twin cams that behaved similar to what you're describing. Only other thing I can think of, and it's a stretch, would be that you're compression releases aren't activating.

Might want to have the dealer look at it. Probably something simple. Good luck. Let us know what you find

 

Any chance you upgraded to the SE plug wires?

I did that a year or so ago and started having the same issue you described. Turned out I got the plug wires connected in the wrong order. lol

 

The bike is stock except for Magnaflow slip ons. I have not modified it in any way and other than a new radiator on the right side, it has had no repairs.

 

Yep, that would do it.
Don't feel bad. Did the 22x upgrade on my 18 and I put the cam bearing in backwards.
Luckily realized my error before I fired it up.

 

My 1st thought...

 

What octane, maybe add octane boost?