"del cecchi" wrote in message news:NTKfb.139

The bigger motor won't burn less gas at the same speed fer sure.
Maybe not much more, but not less.


Bzzzzzzt.

Anyone who reads this NG can tell you that I had FOUR different motors on
the back of my (dearly departed) Four Winns last year.

76ci 80hp - 89ci 100hp - 99ci 115hp - 99ci130hp (crankshaft ratings to keep
this simple)
All tested with a 14, 15, and 17 pitch stainless props.

I can tell you *unequivicably* that in the case of 2-stoke outboards, output
is governed by two factors - spark advance and throttle openings.

If you have to run a 100hp with spark at max advance and the throttle body
3/4 open to achieve a speed of 25 mph but you can take a 130 and do the same
thing at max advance with the throttle body just cracked a bit - guess which
motor will deliver better mileage??

And that's not even accounting for the propping up you can do with more HP.

I'm sorry, but that sentance could not be *more* wrong.

If I ever wanna help this world deplete it's gas supply - I'll start by
putting the 80hp (I kept it) on the PM-II and pulling tubers all day - OK?


-W

"Clams Canino" wrote in message
. net...
"del cecchi" wrote in message news:NTKfb.139

The bigger motor won't burn less gas at the same speed fer sure.
Maybe not much more, but not less.


Bzzzzzzt.

Anyone who reads this NG can tell you that I had FOUR different motors
on
the back of my (dearly departed) Four Winns last year.

76ci 80hp - 89ci 100hp - 99ci 115hp - 99ci130hp (crankshaft ratings
to keep
this simple)
All tested with a 14, 15, and 17 pitch stainless props.

I can tell you *unequivicably* that in the case of 2-stoke outboards,
output
is governed by two factors - spark advance and throttle openings.

If you have to run a 100hp with spark at max advance and the throttle
body
3/4 open to achieve a speed of 25 mph but you can take a 130 and do
the same
thing at max advance with the throttle body just cracked a bit - guess
which
motor will deliver better mileage??

And that's not even accounting for the propping up you can do with
more HP.

I'm sorry, but that sentance could not be *more* wrong.

If I ever wanna help this world deplete it's gas supply - I'll start
by
putting the 80hp (I kept it) on the PM-II and pulling tubers all day -
OK?


-W


My guess would have been the 100. That is the way it works for 4 stroke
motors in cars, and if one believes the fuel consumption curves in
magazine tests of outboards, it would appear to be the same for
outboards based on a little extrapolation.

However experience trumps extrapolation. It certainly seems true that
WOT blows the fuel economy.

del

Yes, once the carbs start to open, the closer you get to WOT - the more gas
it'll suck. What's more unclear to me is if the 115 and 130 (both 99ci) had
much of a difference. I only ran the 115 for a week or so. But it felt to
me like I needed less throttle to get the same speeds even then.

Another thing I could add - is that if you pull a lot of skiiers and toys.
Holeshot sucks gas. The shorter holeshot the better off you are. In that
respect, I'm *sure* I'm doing better with the higher output 99ci than the
old one. That's why I advise people to get the highest output version of
any one particular block. Since they weight the same anyway - might as well
get the most bank for the buck.

-W


"del cecchi" wrote in message news:rv2gb.198

However experience trumps extrapolation. It certainly seems true that
WOT blows the fuel economy.

del