Hi everyone, I recently purchased a 2012 CF Motor 150 Leader, I have just got my learners & this is my first bike. I love it! The guy I purchased it from said she likes premium 98, a service guy of a friend of mine said to only put 91 unleaded in it, which I did, now my bike is running like shit & she has stalled twice  , but still starts no problems  . Any suggestions on what I should do? Flush the engine? Go back to premium 98? Any suggestions, anything would be fantastic. Need some advice ASAP. Thank you 

I run premium in all my small engines. They just run better. No need to empty it out. I also change the oil and sparkplug every time I buy a used toy just so I know it's good.

So you mean stick to premium 98? What I do with the way she is running now? And the stalling? Should I flush the engine out?

[2015 Z Force 800 53/Trail EPS]

It should run on 88-92 unless someone had adjusted something...like the timing. You might need to do some re-tuning ... and you can get 98 Octane fuel down there?? We can't.

I did notice that you said 98. Our premium is 92. And that's what I run. Try some seafoam or fuel treatment  that removes water. I have had problems with not running correct after filling up only to find out there was water in the fuel

Welcome bikerchic.
I bought my CF150 about 11 months ago. Great little bike for short trips and around town. I run 95 in mine and it loves it. It will run on the 91, but doesn't like it and stalls like yours. Stick to the 95 and all will be good. If you have a full tank I would drain off at least half and refill with 95 and it will work its way through. The 95/98 also give better economy.
Also good idea to change the oil, filter, brake fluid and check the valve adjustment. Being a 2012 model it will also need the radiator coolant changed for some new stuff.
Happy riding.

Thanks guys for all the feed back. I really appreciate it. Hanging out for another ride! I miss my bike ☺