Reply To: Wisconsin RBM starting help

[Buccaneer]

I did some experimentation today to see
what “range” my Wisconsin timer has
on it’s spark advance mechanism.

To start it via bouncing if off compression
in reverse rotation, with the timer fully retarded,
the furtherst it will fire from piston TDC is 1.350,
or close to 1-3/8″.

With the timer fully advanced, in forward rotation
of the engine, it will fire .190 BTDC, or about
3/16″.

If the engine is started in a reverse bounce with
the timer fully retarded, it will be running
and hence “firing” about .685 ATDC, until one
can advance the timer.

I’m not smart enough to translate inches of piston
travel in relationship to degrees to TDC. I do
know the piston has a stroke of 2-1/2″.
I suppose one could make a degree wheel to tape
on the flywheel, but I don’t know what specs I’d
be looking for anyway.

The place I’d want it to fire via bouncing off compression
is a little hard to exactly calculate, but guessing
my timer has enough range to start the motor in that manner.

Prepare to be boarded!