High speed stumble...? Scrambler.
My 2007 Scram has had the air box removed, TOR pipes, Dynojet kit, etc. done before I came into ownership of the bike.
The bike starts very quickly and idles fine after a minimum of warm-up. At anything below 4000 rpms it runs beautifully, no misses or hesitation of any kind. No stalling on deceleration.
Above 4000, it starts to stumble, perhaps miss or hesitates; to a consistent degree. It will keep pulling at WOT as far as you want to go- I've had it at 100 mph, but that miss and stumble remains until you get back below 4000 or so.
Is there a "most obvious place to look" first? Dirty main jet in the carb? Coils?
I'm out of my depth, but the fact that it runs so well in all other ranges makes me think it's a specific part of the puzzle.
Any observations or experience much appreciated.