What good is 2 bar (or 4 bar oil) mixture in a 4 bar motor?

Hello , today a few big question marks came into my mind and I ask you if you have an explanation for this ,now to the facts: I had a Romet Ogar 202 with Honda SS50 engine bought from an old pensioner with about 400km run. At the purchase he said that I should refuel the 4stroke engine with lubricating oil (no matter which) in ratio 1:25 so that the engine runs better ,I know myself a bit with mopeds and of course have the old oil plörre directly through fresh petrol because I thought the has had ben brain damage and am now at 1700 km .I read the set of it no rest and have ,experimentally like I am 1 liter filtered old engine oil (Sae 30) of our Ford Transit 85′ in the ratio 1:25 mixed and fuelled . Well the stupid thing about it : the Honda engine ran better ; he had an anstadt 64 kmh at once 72 kmh (in both directions ) and ran much quieter . That could not at all I thought , I expected that the Hobe l maybe 40 creates and a smog cloud behind it does not pull anything?! Does anyone of you have any advice?Can I drive with it permanently or do I have to fear damage? P.S Before (and still) the motor runs quite lean (white spark plug) if that matters.