Most of the information in this thread is incorrect.
The Briggs engine model, type, and trim for the engine used on Ariens Pro and Pro Track Snothros is 25M137-0110-F1
The manuals are here:
It's likely the website has not caught up with the product. This engine is very new and currently only used on most 2011 and newer Ariens Pro and Pro Track Snothros. There is a also summer variant of this engine used in certain generator applications.
The Ariens Polar Force designation has no bearing on where the engine is produced and is simply a unique trademark with a specific feature set selected by Ariens. Briggs makes snow engines both in the US and internationally at their own factories, the manufacturing plant of origin would depend on which displacement is being referred to. In my experience, the quality differences between them are nil.
Lastly, while this engine is in the Polar Force family of Briggs-built engines, this one in particular is the Polar Force Pro (21 lbf-ft torque). It has the features indicative of a commercial grade engine: cast iron cylinder liner, ball bearing journals front and back, and forged crank. It is also the only available snow engine with a separate balance shaft to quell second order vibrations (this is not a simple balanced crankshaft couterweight system). Not even Honda uses this. The engine is butter smooth.
This message was modified Nov 11, 2011 by Snowmann