Sounds like carb issues.Also I always put like 93 or if Im not near a place with it , 91 octane. They really do run A LOT better with better gas. If you can get gas from a place that doesn't add ethanol that's even better. I sometimes even put a tiny, tiny splash of octane booster into it. And my bikes run sweet- well except for the transmission on the Seattle which is a 4 stroke anyway. But for what it's worth I don't think gas exactly is your problem I think it's more likely a carburetor issue or some kind of leak or intake issue.
I also noticed that my 2 stroke(yd100) ran noticably better with premix.(94!octane)
When using the 40:1 ratio.
I've never blown up an engine or had one seize up or any of those type of issues. In fact the only issue I've ever had with my why d100 is I had that crazy racing idle when I would pull the clutch to like stop it would start to race get all vibrating out of control sounding. But when I replace the jug that stopped so there was a pinhole somewhere in my system which I took to be the jug because I had oil stains, but it could have been the offset that I have been using at that time as well that had a pinhole maybe both. You can pick up premix it's a little more expensive than gas depending on where you are but here like in New York 32 oz of pre-mix cost you about seven bucks but they have it at like tractor supply, Lowe's, and home Depot. Most garden stores that sell like small engine trimmers and stuff will probably have it too.
And just as far as gas ratios go I know there's a lot of back and forth about what's the best and what's good for breaking and what's good for you know after you have your breaking mileage behind and I just want to say that I once had somebody told me 40 to 1 from cradle to the grave. And that's never done me wrong.
But that's personal for me you know I know other people have their own preferences and stuff and I've always ran yd100's except my very first bike had a china doll 80cc and that bike did never run right from the start and I have a smaller well I had a smaller West Coast choppers bike that I sold to somebody a few months back they had an anbull 80cc motor on it. And let me tell you something about that quickly too - I know this post is starting to become lengthy - those anbull engines are actually pretty decent. The guy I sold it to kind of beats it up a little bit and he's had no issues except for having to retorque the head bolts on it from time to time but it had acorn nuts on it so I told him to take the acorn nuts off and to go with regular nuts with a washer and a lock washer and since then he's had no problems
