The 9.9 Yamaha's do have a good rep. About 2/3 of my sistership
PDQ36's use twin outboards instead of the diesels I opted for. These
boats are normally used as long term cruisers and liveaboards; most
have a full complement of instruments, fridge, gadgets, etc. The
outboards have a small alternator, plus many of the cats have solar
panels - the newer ones came fitted with 150 Watts of solar. Many
owners get by with that, but carrying a 2K Honda portable genset is
common. Some that have A/C added a real genset. I have a big fridge
and freezer, so adding a genset would have been needed if I didn't
have the diesels.

The two 9.9 HP outboards do a reasonable job of pushing the cat, which
weighs about 10K lbs fully loaded. However, my 18 HP give me an extra
knot, plus big alternators, better fuel economy, and they are more
reliable. The lifetime of the outboards seems to be between 1500 and
2500 hours. Some owners carry a third as a dinghy motor, and swap
them in as needed. One theory is to replace at 1500 hours while they
still have trade in value.

pdqforum.com has a sub-forum for the outboards.


Shaun Van Poecke wrote:
Sorry Matt,
I must have had Honda on the brain last night..... Cant stop riding Honda
bikes either ;-)

The motor im holding out for is a *yamaha* 9.9 high thrust. Ive heard
really good things about this outboard a long life and good running.

Is the same thing true of all high thrust outboards/props? Not knowing much
about it, im guessing a high thrust motor differentiates from a standard
motor only in prop, and the prop would be larger in diameter, but with less
pitch? If so, does that mean any high thrust motor will consume more
fuel/require higher higher RPMs to sustain a decent cruising speed?

Thanks,
Shaun

Next,
Don't hold your breath for a high thrust. You don't need it. Any good
little OB will do fine. Honda's High thrust gets you more stall thrust
and better thrust astern, but at the cost of rev at cruise. My boat is an
S2-7.9 (2.2t vs 1.7t) very much the same class as your Thunderbird. My
2000my (but not many hours) Honda 9.9 Exls will kick me to hull speed at
about two thirds power, but at WOT it picks me up maybe 0.1 knots and
burns twice the fuel. A friend with a sister boat and a newer H9.9 HT has
to crank it up to stay with me. This engine is about 50kg (108lbs)

An alternator capable of ~10 amp at rated speed will add maybe 0.5Kg.
Electric start adds 6+Kg not including cable and battery. While the
alternator is real nice to have, the only reason I have the electric start
is because my wife and daughter also sail and neither was comfortable with
the hang your body over the transon routine to get the engine going. My Ex
shaft added at least 3Kg.

Fair Wind and Smooth Sea
Matt Colie