'11 dyna running poor hot

[FLDavetrain]

So no codes, I've run it a few times and symptoms are same. bike runs as it should for 10-15 minutes then seems sluggish with a changed exhaust note (rough/deeper), less power but no hesitation, backfiring or stalling. Plugs looked little rich so changed them along with a warm compression test that was good in each cylinder. Bike has 24k, garage kept, these days its ridden in 10-20 mile circles each week, sees no rain or hose. Any ideas? thanks.

[Don D]

Dave, likely it is sumping.

[FLDavetrain]

Dave, likely it is sumping.

Not a braking type power loss, more of fuel and timing feel like the tune turns south. Test rides are in town start and stops so I'm leaning towards MAP sensor. I've felt sumping before and this isn't it, this bikes not used a ton so since tune few years back I haven't had TTS. plugged in. I'll grab the appropriate wiring hook up and run data log and check idle enrichment and mark the time it turns on me. I'm told MAP sensors can act like this, run well every time until hot