I tracked down the failure to be worn out clutch discs on my Chinese Loncin 110cc ATV with single speed automatic clutch. I got lots of help on this board from mywifesquad.
Problem now is where to get replacement clutch discs? I am near St Louis, Mo.
Replacing them seems straight forward, I assume they need to be soaked in oil overnight. Although I do not know what torque to tighten the main clutch nut which requires the special tool (which I made by grinding on a socket).
My discs were completely worn out and the atv would not move at all! Two of them appeared to have had lining only on one side which I suspect is by design since lined sides should contact steel plates and not other lined sides, correct?

 

Try these guys..

Kid ATVs | Cheap ATVs | Jetmoto ATV Parts | Online ATV sales | Kids 4 Wheelers | Hastings Minnesota

not sure about the 2 discs with lining on one side..

 

Kid ATVs only sells the entire clutch assembly for $89 plus shipping. Surely there is a parts source for Loncin engines somewhere!

 

A google search got me this...

Chinese Atv Clutch Kits by Clutch Factory - Cd304-110 - Performance Engine Parts - Chinese Atv Parts

 

Thanks, I also found a site that is even having a sale on these clutch discs at motopartsmax. I ordered them last night.
I have only one question remaining, how much torque to put on the nut that holds the clutch discs together. I would think that is critical since too much would cause the discs to lock together on starting and too little would allow slippage. It is a thin nut that would not provide much tightening torque and works against a belleville spring washer and is held in place by a bendable locking tab.
I suspect this is the only real adjustment available for the automatic clutch and would require the removal of the housing to make any adjustments!

 

I saw a video on youtube that showed replacing the clutch discs on a similar engine and he tightened the clutch nut to 20 ft lbs. See it at....HOW TO INSTALL CLUTCH PLATES on Youtube. That clutch had an "actuating arm" which mine lacks and I do not know what it does, mine is purely centrifugal. I plan to tighten the nut until the clutch just starts to drag and lock it there and hope the centrifugal action will drive it when reved up. Surely there is a factory setting employed in assembling these clutches but I cannot find that information anywhere although there must be lots of folks who have replaced these clutch discs on fully automatic centrifugal clutches!