With regards to the Big Bore kit.... I have a 2001 people 50 2t. When I bought it she had an airsal 72cc kit installed (hack Job). A month into ownership, the engine seized. I bought a new kit and replaced it. The piston on the kit that i bought was faulty, and a big chunk tore off of it and ruined the second kit I had. The airsal kits are nickle plated aluminum cylinders and in both cases were destroyed. I decided to bring her back to stock. I was the best decision that I have made.
With the kit on the scoot, I was able to hit 52 mph. It was very squirly at the start too. I had to lean forward to keep the front wheel on the ground.
With a de-restricted stock set up, I cruise at 47 mph, and have hit 50 with the wind at my back. I weigh 210 lbs. The only differences that I notice are at start, she is still very quick off the line, but does not wheelie unless I want it to. Mid range speed and power bog a little at about 30 mph but regulate at about 35 mph. High end, there is not a ton of difference, other than how much more quite it is. I have put 3000 km on the stock set up so far this summer. It is my daily driver, with a 20 mile each way trip to work every day. I would highly recommend keeping your scoot stock, and de-restricting/ tuning to run at these higher speeds. I wasted a lot of time and $ on the big bore set up, when it was really not necessary.
