5K cruising power loss

[Kuprebel]

When I cruise with my VMAX around 5k-5.5k RPM it seems like I need to give it more throttle than I should to continue to hold that speed. Also when I drop out of V-boost it feels like I lose far more power than I should coming out of it. At 60mph its fine its just around 75-95 in 5th gear that I really notice the power loss. Also on decel through those RPM's I get a backfire/popping, so I'm thinking its a lean issue. I've looked around a bit but I'm not entirely sure what I should do about it? (changing main jets/shimming needles/messing with A/F mixture screws?). I'm not entirely sure on my setup as my PO didnt give me much info other than he said it had a jet kit in it with supertrapp slip ons and I have the stock needle. Any help boys? I'd really like to get this thing going full power!:bang head:

 

[Dragmaxster]

I would try 1/2 step on the needle with a washer first and then pull a main jet from the bottom of the fuel bowl to see what size mains you have-After loosening the main jet try a toothpick to get it all the way out---saves some time and effort.
What do your plugs look like? How many discs in the supertrapp now? Where are youe a/f mixture screws set?
You hoses will be in the mail tomorrow.

 

[Kuprebel]

I would try 1/2 step on the needle with a washer first and then pull a main jet from the bottom of the fuel bowl to see what size mains you have-After loosening the main jet try a toothpick to get it all the way out---saves some time and effort.
What do your plugs look like? How many discs in the supertrapp now? Where are youe a/f mixture screws set?
You hoses will be in the mail tomorrow.

Just looked at the exhaust, I have 9 discs on each side. Not entirely sure on the A/F mixture screw but I believe they are between 2.15-2.5 turns out on all the carbs. Kinda scared to pull apart my carbs to get the main jets out because I don't have a sync tool and this is my first mechanical project I've really taken on, and have only done simple stuff so far.