I finally bought Canadian Tire Motomaster formula 1 100% snythetic 5w30 oil 4.59$ in special, not too much expensive! and it take half bottle!
I will flush my old standard used oil, then add the new syn. oil, start engine, then flush again to remove all contaminents, then refill with syn. I also changed the spark plug
the one that was on it was probably the original!, full of dirt and rust.