Good ballpark HP ranges by series: 525 thru 575 - 3.5 hp 600 thru 675 - 4.5 hp 700 thru 900 - 6.5 hp 1150 - 8 hp 1350 - 9hp 1450 - 10hp 1550 - 11hp These are just estimates by me, the fact is these engines don't HAVE hp ratings.
Here is the Briggs and Stratton page that tells you where to look and how to contact them to find out the gross torque or horsepower for your engine. There is also a video explaining the ratings:
briggsandstratton.com/lam/es/support/faqs/engine-horsepower-or-torque-rating
15 HP.
.020
A Briggs and Stratton 17.5 horsepower engine can use any type of small engine motor oil. A heavy duty motor oil is recommended.
7.75 HP
If oil is leaking on a Briggs and Stratton 18.5 horsepower engine, it is likely a seal is bad. It could be the manifold or the bottom seal.
between 9 and 11hp
155 cc
How many horse power is 342cc
5.5 to 6 h.p.
Because Poo gets stuck in them
with a big freagin hammer
5 hp and 6 ft llbs tourqe