Real motorcycle enthusiasts design and mill their own engines. Well, perhaps that’s an overstatement. Certainly it takes to more obsession than enthusiasm to go to these lengths. But this gentleman’s modifications started out simple enough, and managed to make it to the most extreme of hardware fabrications.
The used bike came with a modified camshaft that seemed like a botched job. As he got further into tuning up engine performance the prospect of just replacing the entire thing with his own design started to grow. Using a manually operated milling machine he cut his own molds for the new cylinder head out of wood and sent them off to be forged out of aluminum. They come back in rough shape but he just “filed the cast without mercy” and machined the tolerances to his specifications. Apparently the first test ride had him a bit nervous — he also milled his own brakes for the bike. But after a few times around the block he gained confidence with his work.