I came across an interesting article that, in my option will help answer the above question. The article was put out by Yamaha Motor Corporation. The performance of two Yamaha F150 of 2005, one of them new and the other with 8,700 operating hours were tested.
The results: The old engine was just as quick out of the hole and achieved the same top speed and roughly the same economy at 3500 rpm.
Time to plane 4.5 sec.
Top speed 43.7 mph
Fuel economy 4.56 mpg
8,700 Hour Engine
Time to plane 4.6 sec.
Top speed 43.1 mph
Fuel economy 4.32 mpg
These engines were operating as water taxi boats 10-12 hours a day covering 40 to 45 miles.
Companies who use boats for their business follow the recommended schedule engine service. Another, contributing key factor is the consistency use of the engines. Opposed to commercial boats, a great number of pleasure boats do not get enough usage and are not stored properly.
Regular use of your boat will assist in the maintenance and in detecting issues before they become a problem. Many engine parts get lubricated while working. There are many engine issues that are only detected at running speed. If time does not permit for regular usage, storing the engine according to the manufacturer's manual will $ave you time and money.
The fuel system is a vital part of the storing process and best performed by a trained technician. The life span of your engine can be prolonged by following the manufacture's schedule service, regular usage and proper storing.
JA Outboard Service