Can you all help identifying details and origin of this bike?

[tom keating]

Hello. I am a new guy and would like some help. I am also an old guy (78) and been around motorcycles since I build my first motor driven bike. with a 3 and 1/2 hp briggs and stratton engine. Over the years I have had a bunch of motorcycles. Last month an old board racer type of bike came to me and I have no idea what it is. There are no markings on it, the construct of the engine baffles me as does the drive train, there are no fins on the cylinders, and a number of other things that I can't figure out.

[tom keating]

More photos

[tom keating]

Additional photos

[tom keating]

And a few more

[exeric]

That is a very interesting motorcycle, Tom. Just my observations; looks like a modified bicycle frame, and probably unpredictable to ride over 75 mph I wonder if the motor is a utility motor that was originally intended for a boat as it looks to have a thermo-siphon cooling system. Seems like it would need some kind of radiator for road use. Also, I notice there is no flywheel which could make a lot of vibration that the frame would not like. It does look like someone did ride it, and they possessed a lot of skills to bring it to that level of completion. I'm curious to hear more about it.

[Jerry Wieland]

Interesting piece. While it has a very old look to it one way of determining age is to look at the technique of assembly. For example while arc welding originated in the 19teens it did not come of age until the copper shortages of WW2. This motorcycle has a lot of arc welding on it so post 1945 assembly with parts seemingly older. Just my thoughts.

[kurly]

Excellent observations of a really interesting bike. Does the distributor look like its from a Ford Model A?

[Tom Wilcock]

The engine and the Kingston carb indicates to me it is probably a marine engine in a modified bicycle frame.
Tom