MA: e50 transmission fluid
type f or atf, or possibly sae 30
i run royal purple atf in my puchs
i would get a boss pipe (would match the stock look, would pair perfect with your airsal, and is affordable)
upjet, the side of your bing (im guessing) will tell you the size 12-15 on the side. behind the the side cover with a flashlight u should be able to see it. this will give you a rough guideline to gauge your jetting. garage.1977mopeds or whatever is a great place to cross reference other ppl that have your kit/pipe/carb jet #
test for airleaks. if there is exhaust/intake/head/base your gunna have a bad time: redo gaskets and properly torque bolts.
if thats gucci, next is tuning your clutch. sounds to me like u need more slip, as in delaying the engagement of the pads to a higher rpm. regardless of 2 shoe or 3, remove clutch and
1. check pads
2. consider new springs (blue)
3. MA: clutch tuning
4. the fish scale thing is a thing, but i like just screwing them all the way in and then back them out evenly 2 turns or so
lastly, u might not wanna hear it but if your engine seals are leaking, or for some strange reason the cases arnt sealed with honda/yamabond correctly then this will make it so that when underload it wont go anywhere, but could rev fine on stand.
at which point, and regardless i would stop reading this and go check out travistutorials e50 teardown on youtube, super helpful
i dont post much, but i am completely in love with your mini freespirit, it is so clean and unique. been in the game a minute, and i have to say your bike is absolutely beautiful!
goodluck and enjoy!