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View Full Version : long shaft vs short shaft.


LacLaBicheNS
02-21-2011, 09:52 AM
I found a good deal for a long shaft 20 horse outbaord. I would be using it on my little 14 ft aluminum boat that is supposed to have a short shaft and a max hp of 25.

Can I throw on the long shaft and not worry except for shallow waters

GaryF
02-21-2011, 04:19 PM
http://www.smalloutboards.com/shaft.htm this will answer your question.

bsnyder
02-21-2011, 05:18 PM
She likes the long shaft better:)

nicemustang
02-21-2011, 05:56 PM
I didn't get a chance to review above website but you can run a long shaft on a short shaft boat, it just doesn't perform the same and is not optimal. I think the biggest thing is less top speed if I recall.

bloopbloob
02-21-2011, 06:16 PM
Its all about the girth.......

LacLaBicheNS
02-21-2011, 08:50 PM
Thanks for the serious response and the jokes...

I will grab it. ITs a good price and its been un used for 8 years... Its acutally a 25 horse not a 20 like the ad says.

I will not loose top end speed because I currently run a 15hp, so even with the long shaft I am still putting on a extra 10 horse..so top end will be by far better..

Finally I may be able to get to the end of some lakes I haven't been able to prviously lol

AbProwler
02-22-2011, 08:00 AM
I had a long shaft 25hp.on a 14' Sylvan, it would never get up on plane. I ended up building the transom higher (4") where it mounted. What a difference!!!!

nicemustang
02-22-2011, 09:39 AM
I had a long shaft 25hp.on a 14' Sylvan, it would never get up on plane. I ended up building the transom higher (4") where it mounted. What a difference!!!!

Good idea and easy fix.

LacLaBicheNS
02-22-2011, 10:12 AM
I had a long shaft 25hp.on a 14' Sylvan, it would never get up on plane. I ended up building the transom higher (4") where it mounted. What a difference!!!!

I'd like to see a picture of this if you don't mind.

freeones
02-22-2011, 10:32 AM
For about $300 give or take, and some of your time, it's fairly easy to shorten the leg length on any outboard.

Simply order the required parts, likely just a shorter drive shaft, shift shaft, water pickup, and the necessary seals, and swap them in.

LacLaBicheNS
02-22-2011, 12:39 PM
For about $300 give or take, and some of your time, it's fairly easy to shorten the leg length on any outboard.

Simply order the required parts, likely just a shorter drive shaft, shift shaft, water pickup, and the necessary seals, and swap them in.

hmmm.... thats a thought if the boat doesn't run right I guess.

AbProwler
02-22-2011, 01:14 PM
Sorry, sold the boat about 6yrs. ago. The transom on the Sylvan, has an aluminium angle cap over the wood, it was just a matter of removing the cap, shaping a P.T. 2x6 to the contour of the transom. The only cost was for the 2x6 $3.00 and a piece of alum. angle iron to recap the wood, about $4.00, when I did it in 2001.
I also looked at shortening the leg, even in 2001 it was cost prohibative $$.
Mercurey!!!!!!

Gust
02-22-2011, 01:48 PM
I had a long shaft 25hp.on a 14' Sylvan, it would never get up on plane. I ended up building the transom higher (4") where it mounted. What a difference!!!!

Bingo,,, a long leg on a short boat actually causes the trim to push/shovel water, the aft is too seated for optimal performance. Raising the transom is perfect.

LacLaBicheNS
02-22-2011, 02:34 PM
I don't suppose its a easy answer, but I'll ask anyways. How many inches would I need to reaise my transom? I checked and I can only go another 2 or 3 inches higher or I won't be flush with the rest of the boat.

nicemustang
02-22-2011, 02:41 PM
Difference between a long and a short is 5". So my guess 5" would be optimal.

chubbdarter
02-22-2011, 02:47 PM
transom strong enough for a jack plate?

DOGFISH
02-22-2011, 02:48 PM
To go from a 15" shaft to a 20" shaft you will need to lift it approx. 5". Measure the cavitation plate on the out board from the top of the mounting bracket and it should be with in a inch or two from the bottom of you boat.This website might help you.http://www.smalloutboards.com/shaft.htm