Sidewinder 428 conversion kit

[nightstalker]

I heard some talk about what this chain and sprocket conversion will do to my crf150. I read that the stock 520 o-ring chain is a heavy overkill on such a small bike and it's robbing the motor of a noticeable amount of power . . . almost a big bore kit difference? I've already re-jetted to a 115 main and moved one clip richer, removed the baffle and snorkle and installed a white bros filter. The bike is way more resposive and I want to see what more I can get out of it without spending a lot or rebuilding the engine. Any insights or experience would be appreciated.

[unibrow]

here are some thoughts on the conversion

https://www.thumpertalk.com/forum/showflat.php/Cat/0/Number/712289/page/4/view/collapsed/sb/5/o/all/fpart/1

[Brianc]

We bought a 428 conversion set from Sprocket Specialists. It was less than 1/2 of what SideWinder costs. It made a very noticible difference in performance. Wears well also.

We also tried the exhaust mod that you listed, then we bought the BBR exhaust. The BBR exhaust is much more quite than your mod, AND because of the stepped header design and ceramic coating, we got more power from bottom to top.

Loud bikes do lose riding areas, try the BBR exhaust, you'll love it.