Sigh, today was just one of those in-for-a-penny, in-for-a-pound situations. At each step of the way I just could not resist seeing what would come along next.
To pick up where we left off, the Comet driven sheave interfered with the stock left side jackshaft/swing arm mount.
I could have futzed around with offsetting the motor to the left and moving it forward, but that would be slim shady. I want the motor centered left to right and front to rear on the motor plate.
Remember I swore that I would not cut the stock frame? I cut the stock frame.
I only needed to trim the front of the stock jackshaft/swing arm mount. That piece was redundant anyway since the Comet 20 does not require an external jackshaft. Furthermore, if some day down the road I switch to a jackshaft, well, the stock jackshaft situation would not work with this width tire, anyway.
The whizz wheel came out and made quick work of the haircut:
Now the motor sits where it should with plenty of clearance for the driven sheave:
Next, can I fit the chain between the frame and tire? (Again, sorry for the sideways pictures, but the Forum software flips portrait photos to landscape because it was programmed by Geniuses.)
Yes, it seems I can.
I then slid the sprocket in and used the nasty, rusty original chain as a straightedge to take a more accurate look see:
We are definitely in the ballpark. If needed, I can widen the frame rails at the rear of the seat to give more chain clearance, but I don't think that will be necessary. That additional frame mod is in my pocket in case I need it.
As a result of today's work, I have the following working hypothesis:
- 5 horse Briggs.
- Will need to add an external fuel tank and change the stock carb/manifold.
- Comet 20.
- 84 tooth sprocket.
- Left side drive.
- Motor can sit flat and centered on the motor plate left to right and front to rear.
Things I don't yet know:
- Will the brake be mounted left or right?
- If the brake is mounted on the left, can I fit it between the wheel and sprocket?
- Rigid or swing arm? My preference is to keep the swing arm, but the arc of the swing arm and the chain will be slightly different. Enough to matter? We'll see.
- Will the brake pictured do the job? Anyone work with one of these before?