Things I should check before running a used motor that I bought?

[GAJoe]

While searching for a Walbro carb for my 10HP B&S I found a '94 vintage12.5HP B&S I/C Quiet off of FB Marketplace for $75. Of course the picture looked great; too good to be true.


I went to look at it and it would turn over and seemed to have good compression so I bought it. The carb was pretty gummed up with old gas residue. I think that it cleaned up good, you can see my other post about it.




Judging from the starter I don't think that it has been used a great deal. At home I confirmed compression and good spark on the plug. I plan to clean up the flywheel. Should I try to get some oil to the piston rings or will just pulling the rope several times without the carb or plug get some lubrication where it needs to go. Maybe spin it with the starter after that?
Before I try to start it are there things that I should check to make sure that I don't do any damage? I changed the oil; the old oil didn't look burnt or too bad.
Thanks for your help,
Joe

 

[Auto Doc's]

Change the oil and put a correct champion spark plug in it. This is an older flat head engine and they are bullet proof if maintained correctly.

Adapting it to a later rider mower may be tricky because these did not have a charging system that would operate an electric PTO clutch. A lever operated deck should be no problem.

 

[GAJoe]

Change the oil and put a correct champion spark plug in it. This is an older flat head engine and they are bullet proof if maintained correctly.

Adapting it to a later rider mower may be tricky because these did not have a charging system that would operate an electric PTO clutch. A lever operated deck should be no problem.

It's to replace this origional 10HP:


On this Snapper RER:

that I just refurbished the drivetrain on; new 63 tooth gear, chains, bearings, boots.... and replaced the bushings on the steering.

 

[GAJoe]

I cleaned the rust off of the fly-wheel and the magnito. I put some Mystry Oil in the cylinder and in the oil sump and pulled the rope by hand several times to get the cylinder lubricated some. Then I checked compression without the carb that is waiting on parts. Pulling the rope I got 40psi. Then I got the battery off of the snapper and jumped it to the starter. This confirmed that the starter works and I got 68 psi compression. I also checked the MAX amp draw by the starter and got 174 amps. How do these numbers sound to the guys that have actually checked compression and cranking amps on a Briggs Flat Head engine, 12. HP preferably?