Looking to increase h.p. of my boat

[85Searayseville]

I have a 85 searay seville with a 140 merc I/O. I am currently looking for a way to improve my r.p.m.s. right now I run a 21p prop. for more top speed, but my motor will run above 4000 rpms with this prop. I have a 19 & 17 p. props as well. but they really take away from top speed. i would reaally like to be able to push a little faster. I would love for any help or sugestions.
thanks for the help.

 

[Don S]

Re: Looking to increase h.p. of my boat

Easy.
Bigger engine (V6 or V8), different drive or gear ratio.
Nothing you are going to do with props and a 140 to make it a screamer.

 

[85Searayseville]

Re: Looking to increase h.p. of my boat

Thanks, do you think my 17ft could a v-6? can I use the same outdrive? How would I go about changeing final drive?