Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I admit that by creatively picking the correct carburetor for my snowblower certainly made it run much better than it did without question, what actually made it perform better  was by setting the engine speed closer to what Tecumseh said was the upper side of the governed engine speed.  I was poking around the internet recently and found another forum that had a discussion at length about horse power ratings within the OPE industry.  Frankly, I was amazed at what I was reading.  A number of the individuals that were posting on this subject must have gotten straight "A's" in physics. 

It also pretty much proved the point I was trying to make on another thread on this forum, why engines of the same CC's can be rated at such varied HP.  I look at the engine model on my Toro snowblower being an LH318SA.  This model number always appears as a HMSK90.  If you look up the governed speeds of this engine, you'll notice at least (3) separate governed speeds depending on whether it has an alternator for charging a battery or an 18 watt alternator for Halogen lights, or no electrical options at all.  In the order as just listed, the speeds are, 3,450, 3,600(halogen light equiped), 3,250 (no electric options).  So I ask the question, how does this Snow King 9 HP engine produce the rated horse power if the governor can be set at either of these speeds or anything in-between?  What is the horse power the engine puts out at 3,250 RPM's as opposed to 3,600 RPM's?

Like the consensus was on the other forum, HP ratings are all fudged big time on OPE.  I'd still try to get your carb in order, but I'd also get a good RPM meter on your engine and at least see what it's running at.  If you want performance, look to the maximum rated speed you can run the engine.