How fast could my boat go with a... ?

Higgins79

Seaman Apprentice
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Jul 19, 2012
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35
I have a 1648 Landau riveted boat. It is a modified V that has a dry weight of roughly 250 lbs. I need a longshaft motor and a guy wants to trade me his longshaft 25 Yamaha 4 stroke for my short shaft Evinrude. It's a good deal but I'm afraid a 4 stroke may be too damn slow! If I could get my boat's weight distibution just right, how fast could I go? (My target is 30mph but this may be a hopeless dream :p)
 

series60

Chief Petty Officer
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Jan 4, 2010
Messages
420
Re: How fast could my boat go with a... ?

I have a 1648 Landau riveted boat. It is a modified V that has a dry weight of roughly 250 lbs. I need a longshaft motor and a guy wants to trade me his longshaft 25 Yamaha 4 stroke for my short shaft Evinrude. It's a good deal but I'm afraid a 4 stroke may be too damn slow! If I could get my boat's weight distibution just right, how fast could I go? (My target is 30mph but this may be a hopeless dream :p)

Mid 20's would be my guess. By the time you put yourself, your gear, fuel, battery if you have a trolling motor, your 250# boat is pushing 600#s. What is the boat rated for hp wise?
 

Bob_VT

Moderator & Unofficial iBoats Historian
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Re: How fast could my boat go with a... ?

That is really only 50% of the max hp if I am right. I think that model is rated for a 50 but, you have to check the rating plate.

The 25 Yamaha is only 50% and the rule of thumb is be at 70% of rated power for proper performance.

However,

Having the proper size shafted motor on the boat is better than a mismatch with a short shaft. I doubt you will se 30 but upper 20's is more like it. The Yamaha 4 stroke is a good motor.
 

Bondo

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Re: How fast could my boat go with a... ?

I have a 1648 Landau riveted boat. It is a modified V that has a dry weight of roughly 250 lbs. I need a longshaft motor and a guy wants to trade me his longshaft 25 Yamaha 4 stroke for my short shaft Evinrude. It's a good deal but I'm afraid a 4 stroke may be too damn slow! If I could get my boat's weight distibution just right, how fast could I go? (My target is 30mph but this may be a hopeless dream :p)

Ayuh,... The Problem will be the Loonnngggg shaft motor,... It'll be a Slug, 'cause it'll be draggin' too much, Underwater...
 

Higgins79

Seaman Apprentice
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Jul 19, 2012
Messages
35
Re: How fast could my boat go with a... ?

The hp rating for that boat is 30hp. The Evinrude shortshaft actually makes it go, but it's hard to control since the top stability plate is above water haha. The problem I have is that this boat is TOO light The Evinrude was scary fast (35mph) and it was only a 35hp. My perfect engine would be a 30hp 2 stroke but if I get a good deal on a 4 stroke I probably won't pass it up
 

Bondo

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Re: How fast could my boat go with a... ?

but if I get a good deal on a 4 stroke I probably won't pass it up

Ayuh,... What part of "A Long Shaft Motor Won't Work Right" are ya havin' a hard time understandin',..??

There's more to settin' up a boat, than Just horsepower....
 

Higgins79

Seaman Apprentice
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Jul 19, 2012
Messages
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Re: How fast could my boat go with a... ?

AYUH... my boat has a 20" transom, apparently I didn't make that clear enough for you. Have a hard time understandin'???
 

Bondo

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Re: How fast could my boat go with a... ?

AYUH... my boat has a 20" transom, apparently I didn't make that clear enough for you. Have a hard time understandin'???

Ayuh,... I truly apologize for that remark,.... My Bad,....

I completely misread yer post,... I'm sorry.....
 

Solittle

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Apr 28, 2002
Messages
7,518
Re: How fast could my boat go with a... ?

Gots to throw my two bits in here. I have a 12' tinny with a short shaft transom. I'm running a 75 9.9 Johnson long shaft. While the performance is not optimum it works out just fine. Gets me at 225 lbs and the mrs up on a plane quite nicely.
 

emoney

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Jul 19, 2010
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Re: How fast could my boat go with a... ?

I think you'd really like that Yamaha 4stroker once you put it on. Uber quiet.
 
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