3 times seems like a lot. Is the power adequate before, while warming up?
I've had older, somewhat worn engines smooth out but nothing that drastic a surge in power after warming up.
Thinking some sort of vacuum and as the engine heats, it's sealing itself. But if running well, I wouldn't worry. I would torque everything down to specs. If ya don't have a torque wrench, Make sure everything is at least tight. But be very careful not to over torque and damage anything.
Is it still very cold where you are and how many hours or miles on the engine?
But this will have happened to someone else and they will learn us both. snork.
Did a search but not finding much. If you can and there are no vacuum leaks, post a vid while ridding (sound will be more important) and note at what time you feel (and hear) more power.
(there is 2 "U"s in "vacuum" Man English is crazy. 4 to's, 4 fours...)
2,two,too,to. 4, for, four, fore...Yeah, I know....)