"Paul Schilter" paulschilter@comcast,dot,net wrote in message
...
nffisherman,
I have to wonder how much faster do you want to go? 40 sounds
pretty
healthy to me. If you were into racing I'd understand it or a
professional
tournament fisherman perhaps. I agree there is something to bigger is
better, but at least for me there's financial limitations, sort of
like
return on investments. If the goal is to pull skiers better, perhaps a
prop
change would help at a loss to higher top speed. Please don't take
this as a
criticism, if you have the need for speed and 40 doesn't get it, by
all
means go for it. Happy boating!
Paul

"nfisherman" wrote in message
m...
I have an 18 ft. Lund Fisherman with a Yamaha F115 motor. I'm
thinking of upgrading to the new Yamaha F150, the maximum rated hp
for
my boat. My boat's top speed now is approximately 40 mph w/2 people
and gear. I mostly use the boat for fishing, but there's some
occasional waterskiing.

What kind of performance increase could I expect by adding 35 hp,
assuming comparable props?

Any ideas on the trade in value of the 2000 F115? I'm trying to
decide if there would be enough of an improvement to justify the
cost.

Thanks.

A generally accepted rule of thumb is that speed goes as the square root
of HP (or power/weight). So increasing HP by 150/115 will get you about
15% more speed or 6 mph. Or you could call up Lund in Minnesota and ask
them.

del cecchi