Max Mustermann wrote:
On Sun, 13 Jun 2004, "Lloyd Sumpter" wrote:

Hi,

I just gave up trying to find a used 9.9 4-stroke and bought a Shiny
New Merc
9.9 4-stroke. It's LIGHT!

Anyway, I've always run older 2-strokes and often ran them WOT for hrs at a
time. Now that I have a new one, I'm more concerned. Are outboards (esp.
4-strokes) designed to run WOT full-time? I know inboards are not, but what
about outboards?

The manual doesn't say: just describes break-in period. They say for the
first 10 hrs do not run WOT for more than 5 minutes. After that...?

Lloyd Sumpter
"Skeeder" Mirrocraft 12


Both Harry and Tony are right on target concerning their thoughts on
running at WOT. Though I am running a diesel and expect a longer life, I do
not run at WOT for any length of time.

Consider the following from www.boats.com

In typical marine use, which involves considerable idling and medium speed
operation with relatively little full throttle use, a gas engine can
expect 2,000 hours before it needs an overhaul. A diesel used in a similar
fashion might go 5,000 to 7,000 hours before an overhaul is required. Even
at full throttle, a gas engine is going to need rings and crank bearings
in about 200 hours, while a diesel won't start burning rings or pistons
for 1,000 or more hours.

In a nutshell, continuous running at WOT will likely shorten your engine
life to a tenth of what might be expected under normal use.




I've run our Johnson 6 hp at WOT for hours on end for over thirty
years... the engine has never been apart and I've changed the points
once... do these engines last 300 years or more with more gentle use?

Rob