Every early Briggs (pre 90s?) I've seen has a (relatively) smooth, non-pebble-grain casting finish so I'm leery of inducing one by bead/sand blasting. I have a later model 1996 flathead that is pebble grain and unpainted. By that time painting the block was an unnecessary waste of money...
My "refurbish" procedure on an unknown (craigslist) motor is a total tear-down, cleaning and inspection of parts. The bare block is scrubbed with detergent in a bucket of hot water. If the crank/cam/piston looks kosher, I clean and reassemble.
1. I de-carbon the cylinder head and usually polish it (for kicks). This is actually a periodic maintenance step from the manual
2. If the valve faces are pitted, I have a local shop grind new faces on them. Last time it was free!
3. I lap the valves by hand with valve grinding compound & the suction cup tool thingamajig
4. I inspect the valve clearance and adjust if needed
5. I mask off the assembled block (side cover on, valve cover on, minus the head) and paint as a unit
6. I paint everything else, the tins, gas tank and such separately and carefully reassemble the entire engine when dry
* I don't paint carburetors. They are stripped and left "in the white".
Like I said, I tend to paint most everything separately. I know Briggs & Stratton painted engines after they were completely assembled, and that's fine, but the paint doesn't reach the flywheel side of the block and other nooks and crannies.
Let me know if you require more info. I have detailed files.
Restoring my old boonie bike.....My problem is it will start for a moment, then dies. I need troubleshooting ideas. Please and thank you!
I think you had better start your own thread. This one is misleading,
it's really just about painting.