I have had my sons 70cc atv for about three years... Never had a problem until now... It idles fine, and will run on flat pavement.. But whenever he tries climb a small hill( give it too much gas), or if its under any kind of load.. It dies out. Even on flat pavement it will cut out on him, if he tries to go too fast.. Almost acts like a revlimiter?? It even sounds like one when it starts cutting out.. But if you let off the gas, it will still idle ok... The only thing I have done so far is replace the factory spark plug... As far as I know the carb seems to be ok?? All the adjustments work etc... Any ideas??? It Looks like the 70cc mini XL that raceway sells...

 

3 years without a valve adjustment? it's overdue. adjust the valves before going any further.

 

Will do.. On a side note the spark plug was black(carbon) when I replaced it...