That's my thread on the occ StingRay...
I used a bargain basement LiveFastMotors kit off eBay. It's 55cc and needed a little work. I'll need to update the muffler, clutch handle and a few other odds and ends before I'm done.
I'm using a 48 tooth sprocket It does okay. I'm going to update it with a 44 soon. I weigh in at just under 200lbs THe bike is a heavy tank. AS I've used it more the lube I put on it has worked it's way in and the clutch and sprocket all roll much more smoothly. IE pedal starting is easier than when I first got it. I've gotten it up to 33mph but usually cruise around 20 to 25 and it feels pretty goo. HTe smaller tires seem to allow for larger sprockets with more speed...
I would recommend Barry's mount off ebay for the chengine when/if you get it he's
here on eBay. If you send him a message from eBay he'll list one with in the hour for you and ship within the day priority mail, well packed and FAST. Barry kicks serious butt. It will make the install cleaner and easier. With that mount I'm able to move my engine my millimeters to get perfect alignment.
When/if you go with the chengine get a good chain breaker and 2 chains, the throw from the front of this bike to the rear is LONG. Or... I used an OCC chain off another build. I had to remove about 10 links or so... The chain works perfectly.
I've got a standard muffler and it's been giving me fits. I'm about to go loctite and double nut everything together and see if that helps.
I can't speak about eh larger 4 stroke kits, but I do like the look of the chengine on this bike as a buddy/coworker of mine said- "It looks like a harley traveler that shrank in the wash."
AS for starting off, with the 48 tooth sprocket I pedal to about 7 miles an hour and she pretty much starts right up. WHen stopping and starting at a stop sign I can either push off with my feet and pedal just a few strokes. If not then she stalls.
I am very happy with my livefastkit... His customer service has been excellant and based on that I'd ecomend him.