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


The answer is no. No production outboards will have a long life if you
run them for long periods of time at WOT. For sustained operations, I'd
suggest no more than 70% or so of max RPMs. I run my 225 Yamaha
four-stroke at no more than 4500 rpm (redlined at 6000 rpm), and usually
at around 4100.