I have asked myself why I might buy an engine, when these bikes are so cheap I can buy a complete package. Worse, they all seem to be bespoke, so you have to buy the same engine, or go to work modifying the frame!!!
Why bother. I am just going to spend the extra thou on the right bike, with the right engine. If I need to buy a replacement, I can see that they are affordable. In fact, so affordable that I can order one, modify it for a race tweaked replacement (for my racing circuit participation LOL!!!!!). Coo