Richard Casady wrote in
:

On Mon, 01 Jun 2009 19:13:35 +0700, Bruce in Bangkok
wrote:

If you do much cruising I suspect that you will wish you had an
inboard though. Or a bigger fuel tank. An outboard surely burns a lot
of fuel..

Four cycle spark ignition specific consumption is the same inboard,
sterndrive, outboard, long tail motor, sail drive, and airboat. Half a
pound pre hour per horsepower. As much as double for fuel cooled
racing mills. Getting the oxygen into the motor is the problem, not
fuel. A lean mixture uses all the fuel. A rich mixture uses all the
oxygen and gives maximum power and a wasteful fuel rich exhaust.
Flames at the end of the exhaust system. With fewer than one set of
jets per cylinder, carburators are inefficient, the reason why they
have disappeared from autos. Two four barrels or four two barrels for
a eight, a common arrangement for muscle cars. As it is wilth EFI, you
get enough fuel in the exhaust to require a catalytic [spell checkers
are grand] converter.


My 250cc Honda Reflex scooter, water cooled, 4 cycle, 1 cyl, float carb,
electronic ignition with electronic enrichment instead of
choke/accelerator pump, variable V-belt drive (no transmission just one
reduction gear in wheel) gets nearly 75 mpg if I stop driving it like I
stole it. Its top speed is near 80 mph on level ground. Sustaining 75
mph on the interstate doesn't seem to bother it. Starting, even in
winter at 25F, is instantaneous. Power is smooth, except for a little
lag as the centrifugal weights, built inside the engine-mounted pulley,
fly out around 40 MPH into medium ratio. Low ratio weights fly out at
about 55 MPH. Engine speed is lower at 70 than it is at 60 because of
the crazy variable V-belt drive. There is no "shifting". The
centrifugal clutch is inside the engine and engages the V-belt pulley at
2200 RPM so you can idle disconnected (1400 rpm). 60 mph is about 7000
RPM. My old '60-something Honda 90cc bike ran 12,000 RPM for years.

It's an amazing technology and dirt simple. A counter rotating weighted
shaft in the engine makes it have zero vibration...very smooth/quiet.

"How fast will it go?", is always their first question. I tell them,
then follow up with, "It would go faster, but it's only running on one
cylinder.", trying not to laugh.


--
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Larry

"You meet the nicest people on a Honda." - Honda ads, 1960s