Briggs & Stratton vertical shaft comparability with larger engine sizes

[Fabian]

What are the physical internal differences between the 8hp and the 12 hp engines?

 

[bertsmobile1]

Briggs did what most makes did.
Started with a bore & stroke for one series then either stroked or bored it go to the next series
Within a series they used various devices like a smaller carb, or smaller jets or a restrictive manifold to get the 1/2Hp incriments
The first number is a 6 digit number so your current engine is 091702 with the 09 being the displacement in cu in.
Usually within a single series there was usually a 2 to 3 Hp range.
This will explain it better than I can

http://www.stens.com/assets/media/pdf/2012_engine_model_number_guides.pdf

I am not conversant enough to tell you the exact differences from spec to spec however most can be found here

https://www.smallenginesuppliers.com/html/engine-specs/briggs-engine-specs.html

And you need t remember that your shredder uses an obsolete engine so you are looking at the differences between one obsolete engine and another obsolete engine.

 

[Fabian]

Could it be assumed that there should be a lot of 12hp engines floating about as they would be the more common engine size used on ride on lawn mowers?