I bought a $35 RK non-o-ring chain to verify I had the engine aligned properly. The chain run is spot-on.
The only minor issue is that the chain rivets barely graze the inside brake pedal boss on the frame. Since I need to fabricate a brake pedal anyway, it won’t be much of a bother to slim that down a little.
To adjust the chain tension, I took the rear shocks off and moved the swing arm through its travel. The chain has the most tension right where you would logically expect: right when the rear wheel axle, the swing arm pivot, and the counter shaft are all lined up. With the suspension in that position, I adjusted the chain slack to about 1-5/8” of play. I then reassembled everything. With the bike unladen, the slack was at 2-1/8”. That’s only 1/4” difference, and the chain wasn’t able to contact the top of the swingarm, so I don’t think any additional tensioner necessary. However, the chain can hit the cross-tube under the chain, so I might need to add some sort of plastic chain guide or rub strip there.
It was such a nice night that I snapped a few more photos while the bike was out in the driveway.
This photo make evident how the engine is offset to left in the frame:
I haven’t figured out tank mounts yet, but I couldn’t resist plopping it onto the frame for a minute.
