I have searched and searched for a solution to this with no luck. I have tightened the chain almost to the point of needing to remove a link in the chain. Not sure how to do that. So any assistance in removing a link would be appreciated too.
Even after tightening the chain the 110cc continues to throw the chain when my son is riding it. My yard is bumpy in certain areas and maybe this is why the chain keeps coming off. I also continue to hear a tinging sound when he is riding it. I think this sound is coming from the chain. Not sure.
The front sprocket seems to have too much looseness to it but I have no idea what I'm doing. Maybe it is supposed to move some. It moves about 1/4 or so side to side.

 

How are your swing arm bearings? Jack up the rear wheels so they are off the ground. Grab the rear axle / wheels and try to force them side to side. Any movement? Pay particular attention to where the whole rear axle assembly bolts to the main frame. That is the swing arm pivot point and bearing failure here will cause the chain to come off.

Also check the alignment of the front sprocket to the rear sprocket.

 

Jacked up the rear wheels and did not receive any axle movement. I did find the reason behind the tinging sound I've been hearing. There are 2 metal cylinders around the shaft from the back wheels to the center and that is what is tinging. The chain does have a side to side movement when rotating the rear wheels. I believe this to be the front sprocket having more movement than it should.
How can I tighten the front chain sprocket? I could try this and maybe get closer to a solution before taking it to a shop.

 

sorry i'm not real familiar with your quad. but do you have one or two of this style of chain tensioner located on your rear axle?
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if so, that's how you tighten the chain. if not, then there is another procedure to follow....

 

The middle one is the one that is on it. There are actually one on the chain side and another on the disc side (not sure what this is for) I have tightened both to the same distance. I figured if I left one off set it would be bad.

 

I am having the same issue with the chain being thrown off due to the front sprocket having movement. Since there is no way to tighten the sprocket; due you purchase a new one to fix issue? Thanks.