Here's the Howhit GY6 150cc hill climb-
http://www.youtube.com/watch?v=PXwyqDgaj6E
Here's the Honda TRX200SX hill climb-
http://www.youtube.com/watch?v=qeLiHitTwjw
There are several new video's with this engine if you care to view them- here's my channel-
http://www.youtube.com/user/metalstudman1?feature=mhee