How to Build a Mounting Plate
An engine mounting plate that allows the engine to be moved back and forth to remove the slack from the chain is needed.
All engines use the same mounting hole pattern. If you are going to make your own, follow the pattern shown in Fig. 1.
You'll need a way to cut the holes in the plate. A jig saw with a metal blade would work. Some have drilled lots of holes and then used files to cut away the rest of the material. A cutting torch would work as well.
But buying the plate is often cheaper and much less of a pain. We purchased an 10" x 6" x 1/4" piece of metal in 2005 for $9 locally. A parts house was selling a mounting plate for $7 with pre-cut, pretty holes.
During the frame mock-up, don't finish weld in the mounting plate. Though the drive wheel can be adjusted slightly with bushings, you want to make sure the drive assembly will all line up. Better to leave it off until the rear is assembled.
When you do have the rear drive assembled, install the engine and clutch and inspect for mounting position (Fig. 2). Then finish weld.
Some kits are sold that use rubber donut dampeners to limit the vibration. We've used them in the past, but they're not a necessity.