80w-90 gear oil in a 2T moped

[Japanese]

Hi everyone,
I have vintage 50cc 2 stroke moped that requires EP90 gear oil for the gears that share the same oil with the wet clutch.
I was thinking initially to get some 10W40 or 20W50 motorcycle oil, but decided to follow the manufacturer requirements because that thing has a small engine and it gets very hot.

So I got Motul Gear oil 80W90 (mineral) as the closest to EP90 which I didn't find (Castrol has it for vintage cars, but saw it too late). The Motul oil has MoS2 (molybdenum bi-sulfate) and is high viscosity oil KV100*C - 21.7 cSt.

My question is:
Do you think the wet clutch would slip as that oil has moly and probably other friction modifiers?

Motul 80W90 Gear Box - tech data
https://azupim01.motul.com/media/motulData/DO/base/GEARBOX_80W-90_en_FR_motul_35100_20210810.pdf

Thanks.

 

[GR_CoB]

Hard to say. Not many mopeds around here, but many cases of different motorcycles (with shared clutches) reacting differently to the same oil: some slip the clutches right away, some start to slip after a couple thousand miles, and rest don't seem to care and have no slippage ever.

Motul does seem to meet the "Extreme Pressure" spec of the EP90, so most likely you're good. Another good option would be this:

 

[GSCJR]

If it were me, I'd look for a GL-4; Red Line MT-90 comes to mind.