OK so a few weeks ago I bought my son a mz 100cc ATV after reading on here a few things I just decided to buy a new carb I installed said carb over the weekend fired right up runs great but I seem to still have a slight problem with it it seem when us going up hill if u let off the throttle it almost dies out then stops moving like its not getting fuel I'm gonna go get a Jew air filter for it but does any one think maybe the petcock is bad and not letting in enough fuel or carb just needs some tweaking thanks

 

did you check the float level? since it only happens going up hill it sounds like the float level may be to low starving it of fuel

 

Check the on off switch first. These get clogged easy. Just put the switch on off, remove gas line, turn gas on and see if there is a steady stream of gas leaking out. If so then check the fuel lines. If they are good to it is something to do with the carb. Make sure it is set correctly and the float is moving properly. Also make sure you use supreme gas in any small engine that could cause this too.

 

No I didn't check anything open the box and installed it how it came how do u check float level

 

Make sure it is moving right and not sticking. Look on YouTube you should be able to find a good video describing how to do it. Might have to look up Chinese atv carb clean to find one.

 

Clean. The carb, sounds like something floating around and plugging the main jet.
FYI: the on/off switch is on the handlebar. The petcock flows fuel. If the petcock is flowing properly, it will be enough. It isn't running out of fuel.
Non ethanol fuel is what should be used to help prevent carb problems.

 

Carb is brand new so I know its not dirty running high Tess gas with the suggested 32:1 mix I'm not sure if the petcock is flowing enough or not have tocheck it out

 

How big are the hills and what's your son's weight. You can get trash in the new carb you should put a 1/4" in line fuel filter between petcock and carb. Is it an auto or shifter trans?

 

Have an inline filter installed already hills arnt really that steep he prob weighs around 60-70 lbs and its a full auto machine hit the throttle and go

 

Checking the petcock is easy. Just have a container. Disconnect the fuel line at the carb and put in container. Open the petcock to see if you have free flowing fuel. If not, you can buy a replacement one on ebay for very cheap. Petcocks also have built in fuel filters that can get clogged.

Also, is this old gas or did you drain the tank and out new fuel in it?