Hello dear community, today I wanted to do something good for my 95 Honda SFX 50 and replaced it with a new spark plug, air filter, rear shock absorber, new illuminants (halogens), new V-belts and just the transmission oil. I used a workshop manual and also from Castrol the oil selection help. My scooter gets 100ml 10w40 oil. I took extra from Castrol the MTX 10w40. this was red. Oil drained and filled up until it ran out again and then quickly I drove a lap afterwards, of course moderated and not immediately full gas. arrived at home, I once turned the rear wheel and had to find a “singing”. isn’t that normal? that the gearbox skyrocketed. before it was a grinding sound. The transmission oil was safe from 1995 and was really slimy, green, black, dark. the new is red. am grateful for every advice. mfg Deniz