Thanks for the reply! 
Your post brings about a few new questions, though.
[quote]55mm/56mm big bore… avoid the ruima kit, its horrid, just bore out the stock cylinder and replace with new pistons and rings, the finish on the original yamaha cylinder is good… if you have an original!.[/quote]So… I just remove the cylinder, go to my local machinist and ask him to bore it out to 55-56mm, and I ask him for piston and rings to fit the over-sized sleeve? That’s it, right?
My sleeve isn’t a Yamaha one. It’s a year old made in Taiwan after market sleeve. It looks identical, though, and it’s been very reliable. Can I bore that one? Worth a try? I can get a brand new one for NT$900 including piston, rings and all gaskets (made in Taiwan). Not a big risk if I end up disliking the result, I suppose.
[quote]stock carb… sounds crazy but believe me, its perfect for the bike, even when tuned and if setup right you can still use the oil tank.[/quote]I over-sized the piston a few years back on this BWS. Not a big bore. Just a maintenance bore. I was never able to adjust the carb properly after that. I had it set so that all would be fine. Acceleration,good idle, everything. But the bike was rough when compressing/when decelerating. It wasn’t smooth. If I reduced the amount of air flow, the bike ran smooth when decelerating, but it was idling rough. I got used to it… Rode it like that for about a year. Then I put on this cheap after market sleeve on it and it felt like heaven when decelerating. No jerking, no burping. By that time, I decided that boring the sleeve was silly. I can do a maintenance bore for NT$500 or I can buy new for NT$900 and have the bike run better. That’s been my experience.
But you’re saying get a BIG bore and use the same carb. You’re right… It’s sounds crazy. Just a small bore made my bike run rough. I’m really curious how you manage to use the same carb with an sleeve that is nearly 50% bigger. I’m keen to give it a try when I get a chance, but how do you go about setting it up properly? What would I have to change/adjust? Can these mods even be done while having the bike run smoothly all round? I mean, do you have to trade in anything for the gain of power?
[quote]chickenstop pipe… if you saw my bike you might of noticed it, looks rubbish but its secretly the pipe that makes the most power whilst being road legal … works with 135cc too!.[/quote]I had to google the terms “chickenstop pipe.” 
Very few results other than links to your website. The chicken muffler is just a performance muffler, isn’t it? Like a disguised straight pipe? Very loud and obnoxious? I have one of them on my scooter already. :neutral:
As for the clutch, I’m not sure what you mean by “something strong.” The DIY shop where I buy these parts have an array of different brands. The best I’ve used so far is made in Taiwan by KOSO. They are some of the most expensive parts, too. As for the spring, the BWS calls for 1100rpm stock. I put in a 1500rpm spring on mine. It’s harder on the belt, and it makes for a louder bike at take off, but it does add some oumff off the get go.
What would your recommendation be for a clutch? I have to be able to buy it locally. I’m not keen on importing parts.
Sorry for the long post. I have my own little work shop in my garage, and I’m always doing something on my scooter. I’m genuinely interested in some more info.
Cheers!
marboulette
