final update:

I worked on this thing for about 40 hours Christmas week. Would not pull itself uphill. I changed the front sprocket with a CR80 front (all I could get from my local Suzuki shop to fit) and it made very little difference.

Took it back today and got my money back. I say stay away from all Chinese junk. Definitely stay away from the centrifugal clutch models. It seemed like mine just couldn't pull itself without some momentum.

Seller tried to tell me "break in period" and "adjust this and that" blah blah blah. Bottom line is if it is junk, you will get burned sooner or later. I guess I was lucky that it never performed at all or I would be stuck with it.

Tonight starts my search for a name brand ride for my 5 year old daughter.

F Chinese junk for making me lie to my daughter about the piece of crap Santa left her and had to get back.

 

Little late in the game but got a 50 cc for six year old girl last year, unassembled. Prior to christmas, put it together , installed some accessories and went for a test drive, sluggish starting off but would go along fine,I am about 150lbs, idle great but had no get up and go, christmas eve after putting the word out this is the tip I was given, We'll send you a new front sprocket but the problem is the valves are too tight. Yeah right! Told a mechanic about it took it to him and he showed me how to do this, THE DAMN THING WORKED! She stays right with her friends on the trails, but she has unfortunately grown 4 inche this year thus almost outgrowing the bike. This bike is also fully auto no shifting, the set screw on the side of motor to "adjust the clutch" is only a plug to keep the tranny oil from coming out. Trust me next time it will be a jap brand!

 

Your motor is definitely not too small. My daughter's little Arctic Cat DVX50 can easily make it up a steep hill with a 260 lb. plus rider on it.