Long awaited second build Diamondback

Here is my second bike:
Diamondback Sorrento 21 speed

26 x 1.95 mountain bike tire front 50psi, v brake
24 x 1.75 rear 35psi(max, little soft for my taste)
pedal side chain temporarily disabled, looking to go single speed bmx gearing

bgf 50cc engine
2.5 liter tank 40:1 synthetic ipone 2 stroke oil 93 octane ethanol free gas
nt carb with 72 jet clip in 2nd from bottom position
stock cdi
*44 tooth sprocket #41 chain
*stock chain tensioner w/ arrow case saver
torquer 2 pipe(works better for me than bgf banana pipe and stock pipe opened up)

tops out at about 20mph
can start with a slight roll and pull from 0-20mph

things ive tried and removed:
77 jet(too too rich)
bgf banana pipe(loud and less power)
jag cdi(still can't get this to work for me)
arrow reed block(leaked and bogged at full throttle)
Ive gotten it to run clean, and unless i find some quick simple bolt on performance upgrades, im probably going to save them for my other builds in the future. Ive been curious about better 50cc's but i mostly need something built for torque and 20-25 is as fast as i want to go on this bike.
Also looking at better low seat option. I love riding this bike because the seat is much lower than my other bike that goes 38mph. The question is do i want to get there real quick, or comfortably.

just ordered cst cyclops tire for rear 24x 2.4 hope it fits, expect a much smoother ride.

Yeah BBB, seat is super uncomfortable. I also seem to have lost the original seatpost and had to make shims to make this post fit. The post tapers at the end and my seat has slid down and rolls around. I would like a better seat, but i kind of am looking for a cafe racer style seat and not a traditional bike seat for this bike. I definitely know that the comfortable seat i have on the quick bike is really wide and doesnt allow me to move much to shift weight on the bike.

Other thing i noticed is this the 50cc is louder and slower than the arrow motor. I expected one but not the other.

To do list includes:
single speed chain drive
better seat
24" cyclops tire install
side mount kick stand
fix chain tensioner(wheel bearing worn out)
monitor condition of rag joint (looks raggedy)
wrap exhaust(ouch)

sale of this bike is in process. I reverted it back to stock. The only upgrades are mounting bolts, #41 chain, big springer seat, case saver, cateye speedo, exhaust wrap, b7 shorty plug, ipone strawberry oil. stock tensioner really stinks but teh case saver seems to tame the slack.

my friend is buying this bike, pending a paycheck. so long diamond back, happy trails.