Welcome Kymco Owners!
Probably work fine. I have used so-called "Full synthetic" here in US since the first oil change with great/good/normal results. Any oil is better than no oil!I am very partial to the DT300i for many reasons and I will bet you will be, too, if this one is basically sound. You best try to straighten the fins on that radiator....
ouch, that radiator looks awful!regarding the oil, yes, that oil is fine but you unless you have a wet clutch that shares oil with the engine there's no real need for motorcycle (4T) oil. Won't hurt anything but not necessary.
Absolutely! I missed that. Use good grade of car synthetic. Cheaper and gooder! No wet clutch in that baby!