This is an update report.
Now that I'm used to riding Stunner I can tell you what it's like to ride. I have almost 200 miles on it now. I'm pretty sure the ones of you lucky enough to ride Felts won't be surprised to hear me say, this is by far the best motor bicycle I've ridden. With the fat tires and long wheel base this bike steers better than any of my other bicycles, especially at speed, and has really good ride quality. Actually it feels more like a very light weight motorcycle, than a bicycle. I attribute most of this to the 48" wheelbase, and very rigid steering.
When I first got this bicycle I had real reservations about the handle bars. The bend seemed weird, and they don't have much rise. Compounding that, the steering stem has very little also. When I ride a motor bicycle, I don't like to have to bend forward to reach the bas, not even a little bit so I was kind of worried about this set up. Another thing that concerned me about the bars is, they're 31mm at the clamp, tapering to 7/8" at the grip end. That makes it difficult to find replacements without changing the stem too. But I'm happy to report all my initial concerns were unfounded. What I failed to appreciate was that 31mm bars are very strong. There's almost zero flex. In addition to that steering stems for threadless steerer tubes are a lot stronger than the threaded kind.
Concerns about the bend in the bars turned out to be unfounded too. Even though the stem is low, and the bars only have 4" of rise, they have 8" of pullback. That brings the grips back far enough that I can sit almost totally upright exactly like I like. The width is relatively narrow at 24", which comes in handy in traffic.
The Atomic BB had a similar riding stance when new, but it wasn't comfortable at all, because with a 4" shorter wheelbase, it put the handlebars in my knees when making turns.
I dream that someday I'll build a new motor bicycle that will have zero issues when the bike is new, but so far that dream has eluded me. I've had no issues with the motor at all, but there's been a few minor ones with the chassis. After adjusting the chain tensioner, I must not have tightened the screw enough, and about 50 yards out of my garage the star wheel fell off. I eventually found all the pieces in the street. The screw 2 days later. That caused some minor scratches on the inside of the rear wheel stay by the tire. Not really noticeable though. The biggest failure was on my first kind of long ride. The pedal side rear sprocket fell off the hub. I was able to motor home though. The last issue I've had is with the drive chain rubbing the seat stay. Because of the motor mount offset to the left, it means the rear drive sprocket has to be jacked way out there to aline with the front sprocket. This puts the rear sprocket really close to the seat stay. I noticed this initially before the first start up, but I thought I had made enough clearance by putting a washer on the axle between the hub and the dropout, but what I didn't realize was when the chain got a little loose it could whip around enough to lightly touch the seat stay. Adding a second washer seems to have cured that problem. That's pretty much it for the issues.
As far as actual riding, I love this bike. The motor seems like a hero motor. That's slang for a stock motor with more hp than others just like it. It's a twin to the one in Atomic BB, but that motor just doesn't seem to have as much umph as this one. There's only 2 mph difference in the gearing, but this bike easily will over rev, and run just as fast as the Atomic BB, this bike has a hint of acceleration even going uphill. I can cruise at 32 with less than 1/2 throttle. Whacking it at that speed gives a satisfying sound and feel of acceleration that none of my other bikes have had except maybe the built up, but short lived motor I had in the Cadillac.
Next gallon I'm going to 40:1, and probably rejet after that.