JR Weiss wrote:
"Rick Cortese" wrote...

Slow in the group so I figured I'd waste some bandwidth. Checked the mileage
and my boat with an 18hp two stroke only makes 2-3 mpg. I figure it is mostly
because I usually go sailing with my son so WOT for 7-10 miles to get where
the winds are to his liking and same drill coming back after the winds die.

Just my guesstimate but we seem to make ~5 knots at 1/3 throttle and ~6 knots
at WOT. My GPS went down for the count so I have to get a new one before I can
get good data.

Is this about right for a hull that is in sore need of a bottom cleaning?


It appears you're wasting fuel at WOT. Is it really worth all that extra fuel
to save 20 minutes? I suspect you could get half the difference (5.5 kt) with
1/2 to 2/3 throttle. You might get double that by cleaning the bottom!

My SeaPearl 21 with a Honda BF2 4-stroke got around 45 mpg at 5-5.5 kt and 1/3
throttle. Half throttle got another 1/4 kt at the cost of a lot more noise.



Thanks for the info! I guess I should provide a bit more myself. In
strong winds my son will even have the motor WOT and calls it "Power
Sailing". He can't get more then an extra knot or two out of this
combination but I will admit it makes tacks go a little truer: Less lost
speed when crossing over and jib doesn't spin the boat quite as
much/over turn. Still an 18 hp 2-stroke hammering away at WOT while
under full sail is not my idea of a pleasent afternoon sail so I have to
do something to make sure that doesn't happen. Liable to have to tell
him the big motor slipped off the transom!grin

Your mileage makes me envious. Sounds like my best bet would be ~4-6 hp,
4 stroke, and maybe some kind of throttle restrictor plate. Actually I
don't mine what my son does when I am not on the boat so... Your post
made me think it isn't just about the money for gas but the range and
safety margin it would provide. Sheesh! I wouldn't want to carry a 50
gal drum of gas just to get a 50 mile range under power. Matter of fact
I have already turned in an order.grin

BTW: I read a review of the Honda and they echoed your high milage.
Something like one end of Anderson reservior to the other and back on
1/2 gal of gas. Probably WOT all the way and 10-15 miles.

Rick