One to 500 is the minimum we recommend rather than a set guideline for perfect power. In fact, the only negative user report was from Scott(Audeojude) who was using the 6 on a load that exceeded 3000 lbs...Hence his issue with the engine reaching it's rated hp. When he purchased that 6(from another dealer) it came with a higher pitched propeller
. The "pig" propeller
was not available for sale in the U.S.(except through us) so he ended up wasting a lot of effort trying to fix an engine that wasn't broken. At last report, he was satisfied, though not thrilled with the engine.
Personally I like the 6, if it is utilized for what it is intended. Boats up to 25' and under 3000 lbs. I like it even better when that load is under 2500 lbs as the closer you get to 3000 the more likely you are to be in a situation that a single cylinder 6 can't handle. People also tend to forget about the windage that a hull can have, which can also work against a small engine. So, I would tell you that you really should go with a two cylinder, 6-9.9, in any brand, as a first choice. A 6 Sail Pro will work for you, but there will be times where you will wish you had more.
The Johnson would be a bad choice due to it being a short shaft and 15 years old. In it's day it was a great engine, but anything over ten years old does not meet the requirement of dependable power. That crosses every brand and model line
. Lot's of individual exceptions to that...But, that is the reason they are exceptions
Current engines I would look at would be the Yamaha 6/8 and the Tohatsu/Nissan/Mercury 8/9.8/9.9. I prefer the Tohatsu, but I am self serving