Fastest motor setup on 170

[Mr. Osprey]

My 75 merc (84') is what I consider starting to lose it's edge. It goes about 29-30MPH now and is used to rarely ski, heavily tubed, and used to wakeboard and kneeboard every weekend (or was now since season is over) and to fish. Obviosly you can tell I need power and most would say get a bigger engine but the 75 was all right in terms of power and speed. I want at least the same power and more speed. I'm curios to see what other peolpe have as set-ups on their 84-85' 170 Ospreys and what the fastest are. Is it possible to reach 40 MPH or higher?

thanks: Mr. Osprey

[Anonymous]

Hello Osprey, I have a 1988 170 osprey with a 130 hp yamaha. It does 55 + with two adults aboard. The boat is rated for up to 130 and I have really enjoyed the extra power and speed when necessary. Most of the time I cruise at about 25-30, but every once in awhile I " have a need for speed" and the 130 really comes through... John

[Anonymous]

what year is the Yami?

[osprey170]

I've got an '85 with a 115 evinrude - I don't have a GPS but my guess is that it will do 35-40 with two adults on smooth water.  Plenty fast for me...

[Miguel]

My 1985 does about 38mph with a Mariner 115 at WOT, with two people and a full tank of gas, cooler and fishing gear.
Is that 55mph a GPS reading?  I would really doubt that is possible, even with a 130.....

[Anonymous]

My 130 clocks at 55 with the boat  speedometer under ideal conditions. I live on a glass smooth river with long straight runs. When I take her to the ocean I have never been able to open her 100% so I'm not sure what she'll do. I've never used a GPS to check the speed but I'm sure it would be more accurate.  John

[RickK]

My 110 'rude pushes my AS at 38 per gps at WOT.  I used to have a 150 on her and that motor would straighten out your hair - didn't have GPS then but would guess mid 50s based on the facelift I would get when I stepped from behind the windshield  

[DoOver]

My 72 17' with an old clam diggers 140 Johnson on a clear night, smooth as glass, did 39.8 mph on my Garman GPS/Fishfinder combo. Two adults and I have a canvas pilot house over the console.
Brian

[RickK]

Since my last post on this thread (see 2 posts up) I have replaced my '88 110 'rude with a rebuilt '98 Johnson 115. I just finished breaking it in and on the last outing was able to take it to WOT throttle for a few seconds .... 38mph with 2 people (gps).  I thought the newer motor would have more top end... (that power at the prop vs power at the head thing)
Could be 2 things I guess: 1) Could be the pitch of the prop? I used the prop from the old motor on the new one.  2) The boat will only ever go 38.  I've heard that you can throw a lot of power at a hull and it will still only go as fast as it was designed to go (aerodynamics, drag in water, etc).
Who knows - I guess 38 is fast enough.

[Miguel]

I´m right there at 38mph with a 115, clear day, still lake, 2 people, full tanks of gas and cooler.  However, I remember someone mentioned about having used a 150hp on a 170.....
I guess this boat is built for a terminal speed of 38mph, and large increases in HP only give small gains in MPH.....  I´ll test in saltwater sometime soon..... This may make a difference.