YCF 50 A Owner's Manual page 124

English
ENGINE OIL
API Classification SF SG SJ JASO MA 2
Viscosity ( weight ) SAE 10W/40*
4 TM
10W40
Suggested oil
Additional Engine Oil Tips
Make sure to use only engine oils that have been recommended by YCF.
Do not use the following engine oils in your motorcycle: non-detergent, vegetable or castor-based racing oil.
Do not use any oil additives.
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