Q1: what components are needed to install a long-shaft engine on a 1985 SPORT 11?
Q2: is there any concern about using an engine with a long-shaft on a 1985 SPORT 11?
BACK STORY
I own a 1986 SPORT 11 with a 1986 Mercury 25-HP engine with short shaft and remote controls. The engine runs--but not very well. [At some unspecified long time in the future] I MIGHT look at a newer engine.
1985 SPORT 11 Engine Shaft Length
Re: 1985 SPORT 11 Engine Shaft Length
The extra drag of an additional 5-inches of shaft in the water will reduce speed and affect the overall handling of the boat.
It can be done, but it's not a desirable thing in the long term.
It can be done, but it's not a desirable thing in the long term.
Re: 1985 SPORT 11 Engine Shaft Length
It will be much less trouble to fix the short shaft engine to run better than it does now. A new engine will be expensive.
There are very few modern engines with short shaft models. At some unspecified long time in the future those engines will be harder to find and more expensive than they are now.
There are very few modern engines with short shaft models. At some unspecified long time in the future those engines will be harder to find and more expensive than they are now.
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Re: 1985 SPORT 11 Engine Shaft Length
I have heard of some people using jack plates, but I'm not sure if one would actually mount securely on this boat.
When I get more time, I will continue working on the engine on the boat now.
A really good deal will come along on a newer engine. I want to be prepared.
When I get more time, I will continue working on the engine on the boat now.
A really good deal will come along on a newer engine. I want to be prepared.
Re: 1985 SPORT 11 Engine Shaft Length
tigerjim1000 wrote:I have heard of some people using jack plates, but I'm not sure if one would actually mount securely on this boat.
Jack plates are designed to increase performance on boats that have correctly sized outboard shafts. I run one on my 15' Whaler, which is designed for a 20" motor and that's what I run. However, I find that I can run with the motor an additional 5" up with very little lower unit in the water and as you raise the jack plate (it's hydraulic) the attitude of the boat improves with handling and overall feel.
I wouldn't recommend a jackplate as a bandaid for an improperly paired motor with a longer shaft as a jackplate also changes the moment arm (forces on the transom) increasing them and over time this additional force could cause problems.
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