by bgsengine » Sun Dec 24, 2023 5:51 pm
Often the HP ratings were also based on the RPM the engine was built to run at , and yes a restricted intake can indeed cut the power output of an engine quite a bit (Think of the Restrictor Plates they mandated at NASCAR superspeedways) So often enough changing out the carburetor for a 3 HP one would give you a 3 HP engine. (Less air/fuel = less power, no?) The lawsuit thingy I think actually came about because of the more common lawnmower engines - Way back when, mowers were built to run at 3600 RPM with whatever blade size the mower maker wanted, but then the Gummint (CPSC) stuck its nose in, and started mandating Zone controls (deadman bail levers, and the like) , and right on the heels of that , started mandating the "Blade Stop Time" - Because a bigger 22" pushmower had a higher blade tip speed at rated RPM (and more mass to the blade, too) they had to change out governor springs to get a lower Top No Load (That's when it became necessary to have to stock 10 or 15 different governor springs instead of just one or two) - lower top no load allowed them to use the same blade brake mechanism to achieve the mandated blade stop time. However that lower top no load also resulted in reduced power output, so the 3.5 HP engines no longer actually produced 3.5 HP (not surprisingly - they were rated at 3600 RPM, and for a 22" mower, RPM was cut to as low as 2800.. More common was the 3400 RPM 20 inch mower, but still not making a full 3.5 HP)
Upshot of it is, they never bothered changing their labelling (You'd have had to have a couple dozen different H.P. labels for any given base model, which manufacturers deemed not necessary, assuming folks would have the common sense to understand that 3.5 HP rating was at 3600 RPM) which led to the lawsuit. I blame it all on the Gummint that couldn't leave well enough alone and let natural selection weed out the idiots.
How poor are they who have not patience. What wound did ever heal, but by degrees? - Iago (Othello Act II, Scene 3)