You can just safety wire the exup open, disconnect the cables, leave the motor in so it doesn't trip a code. It's not needed for performance but rathe remissions. Headers will require new jetting.
You'll wanna just go to a suspension shop to get your "sag/rebound" set up. This will then tell you if your current hardware is proper for your weight or if you need to change springs out. It's usually $40 and takes about 10 minutes. Your mm suspension travel will vary but there's a range you...
Did the surge happen before you changed parts or just after?
You may just need a tune, which would be either an ecu flash, or an installation of a PCV to get dyno tuned. Typically this is the case o fix the powerband which gets hurt by EPA emissions regulations.
I put on hard bags, and bungee cargo net, bungee cords and ratchet straps to tie everything to the back down over the passenger seat, tying off to passenger pegs, handles, and hard bag frame.
Well you asked but the answer is facebook and google and ignorance and ego. Yamahafz1oa is another forum. However it's a dead model bike, that typically kills forums, nothing new is happening so it degrades to oil and tire threads and people get bored and move on.
Check electrical connections and wires under tank, cutting out hard like that usually means electrical issue. Look for worn cables, sometimes it'll wear through and then wires randomly ground out on frame or parts n whatnot. Water can eventually corrode connections, check em, clean em all out...