Welcome to the forum and the addiction. Enjoy the ride.
I have had my 80cc Flying Horse Motor kit on the same bike for over two years now and I use the same
Cheap Dollar General Coastal 2-Stroke 50:1 oil at $0.80 a bottle to a gallon of fuel. I have been running the same set-up the whole time. I paid $120.00 for the kit and $20.00 at the flea-market. I would say I got my $$'s worth. But that's just my experience.
Pablo is also correct that luck has a good part of it but if you purchase from one of the vendors on this site, Luck is on your side. The vendors here are great and they will help out any way they can. If you have any more questions feel free to ask, that's what we are here for.
Once again welcome.
Hope it Helps. I am also a proud member of the 20 MPH. club