Motorcycle Repair: Scooter Idles fine but cuts out on throttle, brand new bike, cutting out

Question
Hi Danee,

I have a Chinese (Boatain) 125cc scooter which runs fine 90% of the time but on occasion it will start and when I give it some gas any more than an 1/8 of a turn it dies.  This happens when Hot and cold and is completely random.  This morning it started and idled perfect for about 5 mins before I went to ride it, when I got on and went to go it just cut out.  After trying to get it to rev a few times it (over about 20 minutes) it worked fine.  Now I have it in the workshop it is running normal and I don't know were to start to look.

 It is a brand new bike with only 50 miles on it, I have adjusted the mixture so it revs to a peak then back 1/2 a turn as advised.  This didn't resolve the cutting out issue, your expertise would be greatly appreciated.

Answer
Your going to have to work with me on this one. you are going to have to carry a screwdriver with you (or whatever tool it takes to loosen the drain on the bottom of the carb). When the machine dies you are quickly going to have to loosen that drain and see if any fuel comes out. If it does not come out you know your problem is starvation of fuel and you can trace from there. If fuel does come out we will go to spark. When it dies and wont restart pull the plug and see if it will spark outside of the engine. Do these first and follow up with me.