I had a Avon 340 hard bottom for about 10 years. Boat was in use over 300 days per year, in salt water. Started out with a Yamaha 15, which seized after only 2 years. The 15 was fine with one or two persons in the boat but struggled with a bigger load. I switched to a Johnson 25 and was very happy with it. It spent 5 days under water at one point (thieves), and started right up after a quick flush and a half can of WD40. On another occasion, the boat was flipped in a hurricane and dragged thru the mud, which tore off the cover. I had to remove the pull start because one of the supports broke, but once again it started right up. This was in the first year that I owned the motor. About 6 years later the boat flipped while being towed off shore and spent about 90 minutes inverted. This time it wouldn't start so I replaced the ignition wires and coils and it started right up. The Johnson 25 is over 16 years old now and the last I heard it was still going strong.
The Johnson 25 would plane the boat with 5 persons aboard and was scary fast with just me aboard.
This summer I bought a new 1999 Johnson 35 military surplus outboard for a 14' aluminum boat. Motor starts on the first pull. This motor has a neat feature which allows it to be submerged to 400' for extended periods of time. It has a 'dewatering valve' which drains water from the carb and motor and allows a flooded engine to be started after a dozen pulls on the starter rope.
The only negative comment on these motors is that they are a bit loud. The 4 strokes are much quieter, but much more heavy and expensive.