What the perfect motor for a 170?

[gw204]

I was just curious as to what you guys think the perfect motor (HP wise) for a 170 would be?  Mine will be used primarily for fishing the Chesapeake Bay and it's tributaries.  I'm not looking to be a speed demon, but I want to be able to turn a few heads when the water is calm enough.  

I was thinking of something in the 90 to 115 range.  Specifially Opti or ETEC when the time comes...unless I'm out of money by then.  

Anyway, I kinda need to get a general idea about this soon so I can determine how large a transom cutout I need.  So, what do you guys think?

Thanks.

[JimCt]

My 170 had a Merc 75 which pushed along at about 32 MPH.  90 will buy you ~40+ and 115 will scare your pants off.

[RickK]

My 115 Johnson pushes the 170 39.9....

[JimCt]

Only eight MPH faster than my 75???

[bamafaninfl]

90 Yamme on my 170 works great.

[RickK]

Only eight MPH faster than my 75???

You must have tested it on a strong tide  
Seriously, the hull is the key, it'll only do what the engineering will let it do.
Hey Bama, what speed on that 90?
Miquel, what do you get with the 115?

[JimCt]

Once the hull's on plane there is no limit to speed.  Checked my speed with two runs 180 deg. apart to cancel out current.  Solid 32 in flat water.

[Miguel]

I´m just shy of 40mph with my 115, per GPS.  That was measured in a calm lake, I assume it would increase a bit on salwater.........

[Deck Daddy]

Had a 90 yamaha on my 17, ran a constant 33 with 2 people and dive gear.

[NIGHTIDES]

Buddy's 17' was rigged w/ a 115hp. Did the trick and allowed him an extra punch in his pocket to get through the inlet in a following sea.

Having that 'extra' also allows you to run the engine easier and will extend the motor's life.

A happy engine  = a happy boater..

[RickK]

On an older boat like mine, that was designed for a 70, the 115 is maxing the acceptable weight limits too.

[gw204]

On an older boat like mine, that was designed for a 70, the 115 is maxing the acceptable weight limits too.

That's also a good point.  I'm sure if I choose to go with a 115 I'll have to rebuild accordingly (raise the floor a bit, foam core in the floor near the transom, etc.).  Weights on the 115 ETEC, Opti, 2-stroke carbed Yammy seem to be hovering around 360 lbs.

20" ETEC 90 - 320 lbs.
20" ETEC 115 - 369 lbs.
20" Opti 75/90/115 - 375 lbs.
20" Carbed Yammy 115 - 358 lbs.
20" Carbed Yammy 90 - 261 lbs.

261 lbs. on that carbed Yammy could be hard to pass up.

Thanks guys.   :)

[Bluesbrother]

Isn't the carbed Yammy 90 a 3 cyl engine? If so it will consume more fuel...

[Pat Green]

Brian, I have a 1970 17 for about 25 years.  For the first 15 it had a 70hp Johnson which was adequate.  When I put a 120hp nissan it screamed(actually scared my wife). The extra weight caused some problems.  It started porposing which a set of trim tabs fixed. I used the fixed type and when adjusted they perform well (about $40).  Also, the new engine style covered both drain holes in transom, so I installed two new drains at floor level with scuppers because with the extra weight the boat was no longer self bailing.  Pat Green

[Pat Green]

Brian, I have a 1970 17 for about 25 years.  For the first 15 it had a 70hp Johnson which was adequate.  When I put a 120hp nissan it screamed(actually scared my wife). The extra weight caused some problems.  It started porposing which a set of trim tabs fixed. I used the fixed type and when adjusted they perform well (about $40).  Also, the new engine style covered both drain holes in transom, so I installed two new drains at floor level with scuppers because with the extra weight the boat was no longer self bailing.  Pat Green