Brake advice to cure my insanity

[itsagz250butitsmine]

I have read about this mod on here, Im just afraid that it won't have the strength to pull it since the bike slows to 55mph on a very slight incline as it stands now, I'm afraid it might make it worse. The only thing I could think of to make it go faster is to set the idle noticeably higher and pull the slack in the throttle cable to get the most that this engine is capable of. I don't know I wish there was a fellow gz rider that was somewhat local that could just say "this is your problem." I have a feeling that the valves just need adjustment maybe. I'm trying to fit that in my schedule , along with sea foam to possibly prevent backfiring after shutting off a hot engine.