. I purchased this 650 about 20 years ago and it has a Briggs 8hp (model 190402) manual pull start on it. I read that electric start was an option for the 650's that year (1966). The tractor has everything in place to be an electric model and I have tracked down a Delco Remy starter/generator and regulator, BUT the engine DOES NOT have a belt pulley on the flywheel and, if I was able to locate a pulley, I don't see anyway to attach the pulley to the flywheel.
There were two models of the Bolens 650 tractors in 1966. ...Model # 184-01 left the factory as a 6hp manual (recoil) start. ....Model # 185-01 left the factory equipped with the starter/generator attached.
Unlike the earlier Bolens Ride-A-Matics where an electric starter kit was available to convert a manual-start tractor to electric-start, no such kit was offered for the Bolens 600, 650, or 750 tractors.
If you look at page 7 of the B&S Parts List: http://gardentractor...0400-to-190499/ you can see the typical brackets and belt pulley used on your existing engine. ...These parts are similar (if not the same) as those used on the model 185-01 tractors.
Your existing 8hp engine needs to have the bosses and threaded holes to accept the starter mounting bracket.
Also, not all D/R starter-generators are the same. ....Some were 6-volt and some were 12-volt. ....Bolens used the 12-volt models. ...However, some different brands used starter/gens which rotated in the opposite direction, so make sure your unit is correct for your engine, and has the correct regulator.