Stick that 27.5 pilot in. If your losing power the more you ride it that sounds like its overheating. Either your way lean on the main or your detenating. Is shee pinging at all? If not jump up on the main, maybe a 330-350
What size pilot do you have in it? That controls your idle to 1/4 throttle with your air screw fine tuning it. Like I said I would job up to a 350 main and see how shee does. When you leave off of your throttle do both slides sit all of the way down? When you just first touch the throttle do both slide lift at exactly the same time or does onen lift before the other?
Then your carbs are not synched. You have to adjust the brass nuts on top of your carbs until they open and shut at the same time. If one carb slide is higher then the other it will not idle right.
I had 320 mains in my shee with T6's and a drilled out airbox with the lid on. You said it was getting hot so you might be on the lean side. Thats why I said about the 350 main. Check that the cut out on the slides are facing the air filters and that you have slides in the correct carb. Check out Nitronate for a video on how to synch your carbs.
What pilot are you running? If the throttle cable isnt working right fix it now before you go and ride it. You might not have it routed the correct way. When you get the cable working right make sure the side are moving right. Did you put the slides back in right? DO NOT grease your slides. I would go up on your main. Maybe try a 350 main. Also what is your compression now? You said you had a problem with it over heating before the mods and the plugs backing out on you. Make sure your not detonation ( I cant spell).
Well of course Howard is king. I listen to Bubba as much as I can and I agree they did but a choke on him and the Obama thing does get to me. He wont let Manson or Ned do a bit about Obama.
And you have 160 mains? Are you sure? You should have more like 280-320 mains. If you do have stock carbs with 160 mains you have some problems. Check and make sure you dont have Keihin jets in there.