Actually the prohibition is on page 7 of the manual. This means we all must abandon our projects and find some approved use for these things. </sarcasm>I found this interesting: On page 6 of the owner's manual it states in bold print "Do not install this engine on a vehicle".
I wonder if HF is catching on?
Nowadays, you must ignore many of the warnings and restrictions manufactures officially state regarding their products. The prevailing wisdom is that the manufactures are using excessive caution to forestall a possible law suit. I'm not so sure that's the real motivation. It may be fear-of-the-unconventional caused by a narrow mindset. In any case, Harbor Freight, and anybody else who profits by the sales these engines, actually is pleased if somebody finds employment for them.