Boat size to motor size???

[chopper_man]

HI<br />I have a 17' Bayliner Mutiny that i have had for awhile now the original motor was a 1978 merc. 140 hp.,which is totally shot now.My question is i have a 70 hp Johnson which came off a 14' old traveller runabout will it be sufficient to push this big beast???<br />I think it would do ok just need a second opinion.<br /><br />Thanks in advance Chopper.

 

[Triton II]

Re: Boat size to motor size???

IMO with a reprop it should push it, but it won't set the world on fire out of the hole or for top speed. Using the 70 on the Bayliner with the prop off the 14 footer it'll struggle big time. Also the transom heights may be different - is the 140 Merc an extra long shaft (25") whereas my betting would be the 70's a long shaft motor (20") in which case you have to get a extra long lower leg which may not be worthwhile. Others may be more helpful but generally a little more info such as model numbers and year of the 70, plus the weight of the boat is required to get good advice.

 

[chopper_man]

Re: Boat size to motor size???

Ok the model # is 70ESL75B 1975 johnson 70hp.,i have a brand new Vortex prop on it now 13 1/4x 17.It was never set up for the 14' anyway came off another boat.The bayliner mutiny's model # is 1700MU hope this helps i have no clue what it weighs.<br /><br />Thanks again in advance Chopper.

 

[Solittle]

Re: Boat size to motor size???

A 70 on a 17'er should do just fine.

 

[05GlastronSX]

Re: Boat size to motor size???

the minimum engine size on my 17 foot glastron is a 90 and the max is a 150...i have a 150 which is much, much more than is needed, but like everybody says, you should never complain about having too much power. i tend to always max out every boat i own horsepower wise because i know that 1. the engine will work relitivly easier at slower speeds and 2. i will have plenty of power to pull 2 or 3 tubers while still having 6 of my friends in the boat. i suggest you find a bigger engine and at the minimum i would say a 90. you would be very happy if you put on a 115 or 135 IMO. thats a big difference from going from a 140 to a 70...thats half of the power you had before.

 

[JasonJ]

Re: Boat size to motor size???

Reprop, and it will work. It will probably only go at or a bit above planing speed, and will not be pleasant with several people in the boat, but will get you by until you find another motor with more juice.

 

[QC]

Re: Boat size to motor size???

IMHO this discussion is primarily about priorities. If your priority is to get it running cheaply and hope that it will just plane, then I'd do it. If it is about trying to replace what you had, then the obvious answer is that you'll be very dissapointed.<br /><br />Shaft length is absolutely a consideration as far as go/no go. But the other stuff is simply based on what you are trying to do and are willing to accept. My bet is this will be about a 20 MPH boat, maybe 25.

 

[oldfordcrap]

Re: Boat size to motor size???

if your just cruisen not water sking and it gets you on the water for no money go for it till you find what you want!!!!!!!!

 

[tx1961whaler]

Re: Boat size to motor size???

HI<br />I have a 17' Bayliner Mutiny that i have had for awhile now the original motor was a 1978 merc. 140 hp.,which is totally shot now.My question is i have a 70 hp Johnson which came off a 14' old traveller runabout will it be sufficient to push this big beast???<br />I think it would do ok just need a second opinion.<br /><br />Thanks in advance Chopper.

Didn't the Bayliner Mutiny come with a 140 HP Mercury Inboard/Outboard ?

 

[NYBo]

Re: Boat size to motor size???

Another ancient thread brought back from the dead.:facepalm:

 

[stylesabu]

Re: Boat size to motor size???

oldfordcrap, let the dead RIP.start a new thread if you something on your mind.this is the 3rd or 4th old thread you have brought back today