Shaft Question?

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
ok Can I put a 20" shaft motor on my boat that has a 15" transome? Or do I need to add 5" to my transome?<br /><br />Thanks
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Shaft Question?

Howdy, Lyman man.<br /><br />Best solution is to use a short shaft engine. <br /><br />Next would be to remove the 5" extender from the leg (if it has one) and convert it to short shaft.<br /><br />Third, use a jackplate to raise the engine 5".<br /><br />Lots of people build up the top of their transoms. I don't like that solution because it compromizes the engineering of the hull.<br /><br />If you can give us more detail, maybe we can give a more definitive answer.<br /><br />Good luck. :)
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

ok how do I know if it has a 5" extension? I have a 1974 115hp Johnson model # 115ESL74B. It has a 20" shaft. My Transom is only 15" what do I do? I thought about building up the transom, but you dont recommend it?<br /><br />Thanks,
 

S.T. Marine

Petty Officer 1st Class
Joined
Aug 13, 2002
Messages
248
Re: Shaft Question?

If your motor is a factory 20" motor which i believe it is you ither need a new motor or rebuild the transom. I WOULD NOT reccomend building up the transom. The only right way would be a new transom. That is alot of work and might cost more than a used motor. I would see how much you are looking to spend first off. That motor will not work on that boat if its a 15" transom. It iwll sit to low in the water. The cavation plate should be even with the bottom of the boat. Hope this helps good Luck!
 

ob

Admiral
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Aug 16, 2002
Messages
6,992
Re: Shaft Question?

What make and size boat are we talking about that has a 15" transom?
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

It is a 1959 17' Lyman wood boat. I just rebuilt the Transom before I got this motor :( I guess I could rebuild it, but my wife is going to kill me :confused:
 

Walker

Captain
Joined
Jun 15, 2002
Messages
3,085
Re: Shaft Question?

I don't think a jackplate will even work on that 15" transom. I think it will scoop water into the back of your boat from being mounted too low.
 

S.T. Marine

Petty Officer 1st Class
Joined
Aug 13, 2002
Messages
248
Re: Shaft Question?

If the boats a nice classic look around for a classic motor. 15" shafts in larger motors are very uncommon. I looked for a year to buy a newer 40 hp 15" shaft and I found a new mariner on e bay and scarfed it up. If you know the motor and you have had no problems with it and feel safe with it redo the transom. If the motors a real gem of a piece look for a motor. Good luck tell the wife the transom is rotted said it was done wrong now it will be done right :D P.S. I have a nice evinrude short shaft motor that would look good on your boat on e bay dont think it go to fast but its the right shaft lenght :p
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Shaft Question?

Lyman Man, Here's a consideration as long as the 115 is not over rated for your boat.<br /> <br />Plate adapter
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

Hey ST how many hp? and what details or link to it?<br /><br />What are the odds of finding someone to trade a 20" 115 hp for a 15" 40 -65 hp motor?<br /><br />Everything on my motor works but T&T and I found someone to rebuild it..
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

WOW OB<br />For that price I can rebuild the Transom, looks nice but I my motor is already too much for my boat so I braced it extra for this motor, I could not beat the price for it, so I know I may never be able to open it all the way up. How can I find out if My motor has that extension in it?
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Shaft Question?

Don't believe it has one at all.That is usually limited to the smaller engines.It is an exhaust housing extension piece bolted between the lower unit and exhaust leg.Yours should be one piece.
 

S.T. Marine

Petty Officer 1st Class
Joined
Aug 13, 2002
Messages
248
Re: Shaft Question?

Lyman,<br /><br /> You might want to downsize the motor you might have a better chance of finding a motor. As to mine its a 3.3 hp i was joking... anyway i would look for a motor or redo the transom it is entirely up to you. I would not use a jack plate. Let me know what you come up with thanks
 
D

DJ

Guest
Re: Shaft Question?

Lyman Man,<br /><br />That engine was never offered as a 15" shaft.
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

ST you got my hopes up!<br /><br />Just playing,<br /><br />Thanks
 

S.T. Marine

Petty Officer 1st Class
Joined
Aug 13, 2002
Messages
248
Re: Shaft Question?

Sorry man i have a realy nice merc 65 that i need to sell its a 20" shaft though... as to that big evinrude i have heres the gem GEM
 

moderator1

Lieutenant Commander
Joined
Dec 5, 2002
Messages
1,668
Re: Shaft Question?

S.T.Marine,<br /><br />We here at iboats generally discourage dealers advertising their wares here. Private transactions are not discouraged.<br /><br />iboats offers engines for sale too. That is why this board exists.
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

WOW ST she's nice, did you do the work? I wish I could find the decals for my motor.<br /><br />OK I have decide the least expensive thing to do is.........REBUILD the Transom.... :mad: But I have a good motor so I cant see not using it...
 

S.T. Marine

Petty Officer 1st Class
Joined
Aug 13, 2002
Messages
248
Re: Shaft Question?

You need decals? Whats the year and hp? Ya i did the work its perty
 

lpkirby

Petty Officer 3rd Class
Joined
Dec 30, 2002
Messages
86
Re: Shaft Question?

Hey S.T<br /><br />Yes I do 1974 Johnson 115HP model number 115ESL74B,<br /><br />my E-mail is lpkirby@ev1.net<br /><br />Thanks
 
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