bad batch of motors , please help

[thescooterguy]

I recently purchased a batch of 49cc scooter motors that i use to make what i call scooterbikes . they are motored bikes the utilized the bike gears , (SEE MY PICTURE GALLERY ) . this batch of six motors all seam to be doing the same thing , they start up initially , but then they get too hot and will not start , ive tried chaing the oil ratio, using diff carbs , better sperk plugs , i just cant figure it out .

 

[Mountainman]

Can you send them back - if you used a credit card - should not be a problem.. If said engines are -- Lemons -- wouldn't want to pass them on to others..
Ride That Thing - Mountainman