On Fri, 16 Sep 2005 09:08:28 -0700, jaykchan wrote:


Actually, I am thinking of 9.8hp because many lakes in New Jersey
(where I live) have restriction to limit the engine to no more than
10-hp. And a 9.8hp 4-stroke engine is around 90-lb; two persons with a
carrier should be able to hoist it. I am currently leaning toward
getting a 9.8hp as long as it can push the 18-ft boat with 4 adult
males on it at 10 to 15 land-miles per hour. What do you think?


I think a 9.8 might be a bit "lean" for that, although I Hear You about
the size. Here, "under 10hp" means you don't have to license it. Then
again, there's lots of 15hp engines around with 9.9 "tags" on them...

As for speed, there's this problem called "hull speed". In most boats,
either you're below hull speed ("displacement mode"), or well above it
(planing). So either you're going about 5-6mph, or 15-20mph. 10 mph is in
that "in-between" area where you're not really doing either. So either you
get an engine big enough to plane the boat (probably at LEAST 25hp for
your boat and 4 adults), or stay in displacement mode at 5-6mph, and you
could do that with a 7.5.

In other words, a 9.9 probably won't go much faster than a 7.5, but a 25
would to MUCH faster. Make sense?

Lloyd