Long shaft or extra long shaft?

[Survivor]

I have a 76 Catalina 27 with the cut out in the stern to mount an outboard. I would like to know if a long shaft at 20" is OK or should I get an extra long shaft. I will be getting a 9.9 hp. Haven't found the right one yet because I'm looking for used but want to be informed for when I find one.

Harris

[rockDAWG]

It really depends on your mounting height. Since you are buying used, you can't dictate what is available. Can you modify/adjust the mounting height? I don't have a Catalina 27, so I am not familiar with the mounting. I have a Catalina 14.2, I have some leeway to play with. HTH.

[JimsCAL]

Had both a 20 inch long shaft and a 25 inch extra long shaft on the Pearson 26 I owned many years ago. The extra long shaft was much better. Prop stayed in the water much better when in choppy seas and pitching. Did have a minor issue with interference with the rudder when under full power so had to pitch the engine back slightly. If the 25 inch will fit its the way to go.

[tommays]

This is a 20" on a temporary mount to move the boat you can see its pretty deep BUT it was still marginal

[dabnis]

I had a 20"shaft on a Coronado 25 which had a pretty good well
arrangement and the prop almost never came out. For a transom
mount I would think you would want the longest shaft you can get
as long as it doesn't interfere with the rudder, as JimsCAL mentioned.
When it gets rough is when you really want to get the "power to
the ground". Although you didn't ask about how much power you need,
from my experience with a little smaller boat, I wouldn't go with
anything smaller than the 9.9 HP. You may also want to check
out the "high thrust" prop options, if available

Dabnis

[souljour2000]

This is an interesting subject that to my knowledge hasn't been properly explored in these forums or elsewhere...Obviously in this discussion we are talking about smaller sailboats but that is what alot of us can afford these days so any pertinent experiences will hopefully be shared by the readers of this thread.
Myself..I have 9.8 sailmaster by Mercury that is from early 90's I believe. It does okay I guess but I ain't had it in 4-5foot seas yet when I can't make sailway. I am planning on getting more weight into the stern and under the cockpit specifically...so as to" plant" the prop better and also in order to get the cockpit floor at least level and the rear cockpit drain on the transom base really draining as the primary the way it should be...Anyways...there is alot on this subject that I feel hasn't been explored...or at least shared...I have a feeling it's been "explored".....I just would rather learn from the map than make it on this one...

[travlineasy]

There is a very simple rule when it comes to outboard motors. The outboard motor's cavitation plate must be slightly below the bottom of the hull. This permits water to flow freely beneath the cavitation plate, which provides the most efficiency. If the cavitation plate is higher than the bottom of the hull, the engine will not function effectively. If the engine is too high above the bottom of the hull, the boat will not ever move. This, however, applies to a transom mount ONLY. Outboard engines mounted on stern brackets and positioned some distance from the boat's transom will still function fairly well just as long as the cavitation plate is still beneath the water's surface. If the plate comes out of the water, which is a distinct possibility with offset mounted stern brackets, the engine cannot draw in cooling water--even if the prop is in the water. The cooling water inlet on most outboards is just beneath the cavitation plate, and while it is self priming, the inlet must be submerged by at least an inch or two in order to function.

Good Luck,

Gary

[dabnis]

Originally Posted by Survivor

I have a 76 Catalina 27 with the cut out in the stern to mount an outboard. I would like to know if a long shaft at 20" is OK or should I get an extra long shaft. I will be getting a 9.9 hp. Haven't found the right one yet because I'm looking for used but want to be informed for when I find one.

Harris

Here are some links you might be interested in:

http://www.sailnet.com/forums/gear-m...-outboard.html

http://www.sailnet.com/forums/gear-m...0-pounder.html

http://www.sailnet.com/forums/genera...-question.html

http://www.sailnet.com/forums/gear-m...owing-air.html

A search will probably show more, but these are good for starters.

Dabnis

[dabnis]

Survivor,

Here are some more, one involves the same boat as yours:

http://www.sailnet.com/forums/sailbo...-outboard.html

http://www.sailnet.com/forums/genera...-outboard.html

http://www.sailnet.com/forums/gear-m...d-install.html

Dabnis

[PaulinVictoria]

I changed the leg on mine to add 5", has made the world of difference.