2006 powermax 150s

[heyhey]

I bought a used 2006 powermax 150s when I was very anxious to buy a quad and had almost no knowledge of what to look for when buying used.So I used the quad for 2 days and on the second day it took about 10 minutes to finally fire up.Once the third day came around I couldn't start it at all.I tried alot and nothing.So I brought it to a Chinese atv dealer to repair it and the guy was clueless.He first said I needed a new carb,then he kept saying it was different things.In the end he said I need a whole new engine or new quad.He dropped my quad off at my house and said it will start if I boost it with the car so that is what I did and I used it for about 3 or 4 hours and then it stalled going through a puddle and wouldn't start so I had to push it back home.I have tried boosting it and cleaning the air filter and pulled out my carb and cleaned it but still won't start.I know almost nothing about 4 stroke engines but I have a little bit of 2 stroke knowledge so I am sadly clueless here .If you guys have any suggestions on what I should do I would GREATLY appreciate it so my $700 investment doesn't go to waste.