warm and weak

i dont know but how come when i go cruising for a little bit and my stock mototr gets warm it gets hella weak. is there something wrong with it or is it like that. it picks up hella slow. but when its just warming up it runs just fine and i can feel the power then. thanks.

intake sensor of some sort, maybe clean your air filter, fuel injectors, etc. just play around with some different fuel additives to clean stuff up, maybe try seafoam. my guess is that when the engine compartment gets hot, the intake sucks in all the hot air and the engine doesnt like it. or intake sensor that senses the temp and changes something to counter the high temps