I bought my son a 125cc Coolster atv from Zhejiang Qiye Scooter Co., LTD. It wasn't directly from them, it was from some fella in Indiana, but their name is on the title. So my son has rode it for I'd say 2-4 hours, about 10 times total. The last two times he's rode it, it seems to be acting up already. It isn't wanting to start for one, I press the start button and it does nothing, I release and press again and it usually starts up then. Then when it starts, it either shuts off within a second, or maybe idles for a couple seconds then shuts off. I've changed the spark plug today to no avail. The guy that sold it to me said to change the oil after running the first tank of gas out. So that's what I did, after it was already starting to act up. I'm not sure if these have any warranty on them, or if they did who I'd even contact to have it fixed. It's basically brand new and already having problems with it. If any one could shine any light in my direction that would be amazing. My son has fell in love with it and he's bugging to ride again.

 

You don't make it very clear, but if by "I press the start button and it does nothing," you mean the starter doesn't turn, it can be a few things, most obvious, a faulty start button. Many of the quads I repair have buttons that you have to press in just the right way to get them to work. Other possibilities include faulty solenoid, or starter motor brushes sticking, If the solenoid clicks when you press the button, but starter doesn't turn, put a 12v incandescent test lamp between starter lead and earth, press button, if lamp lights but starter doesn't work, faulty starter, if solenoid clicks but lamp doesn't light faulty solenoid. The other fault is probably the carb needing cleaning out, dirt from assembly or a batch of dirty fuel, may have got into the carb jets.

 

What was said above... Also makes me wonder about the guy you bought it off... The oil in these is just a shipping oil and bio degradable to if it leaks out during shipping no big deal.. should be dumped before running thats what i did on mine i was told this buy the guy that sold me mine.. For the little bit of oil these things use i used a good synthetic oil.. I lucked out and a local store was getting out of a good oil and picked it up for $2 a jug... im good for years..LOL

 

My bigger question was why it won't stay started after it starts. As it's only been run a couple of hours. I don't know how much clearer than "it does nothing" can be though. The starter not hitting is nothing. You press a button, and nothing happens. It doesn't turn over and then not start, it does nothing. I'm not sure how else to explain it.

I'm not sure if he changed the oil or not before he sold it to me. He just said it's some type of "engine break in oil" and should be changed before long. I did use full synthetic 4 stroke 10W-40 motor oil as that's what he told me to use and I looked up online and that also seemed to be the general consensus. Between that and 15W-40.

 

As I wrote above, there is a big difference between the solenoid clicking but the starter not turning, and nothing at all happening when you press the button. If you are not getting any click, it can be the solenoid but usually the button or wiring to/from it is at fault. Most quads have a lock-out to stop you starting the quad unless it is either in neutral (geared ATVs only,) or a brake on. These brake switches often go bad. Also, I did refer to "why it won't stay started after it starts," clean the carb out.