No the fluid should not be causing that. Not if its made for tranny. I believe I have like a standard 5/10w in mine. Also don’t put too much in. Sounds like the clutch spring are weak.
Update: I have got all the bugs work out of my motor! has been running good until this week when I broke a piston ring on main start.
17 years of karting
2009 NTK Yamaha heavy champion