Long shaft outboard for Oday 25

[dwdooher]

Replacing the outboard for an Oday 25, 1983. I am looking at a Nissan 8 hp 4-stroke. They list a long shaft as 20". Is that long enough. I was going to get a mounting bracket, Gaerlick, with 9 1/2" vertical drop. Is that long enough or do I need to get a 14" vertical drop.

Thannks.

Dan

 

[Ward H]

Welcome Dan,

Most people recommend the XL 25" shaft for sailboats. Unless you are on a protected lake, rough water may cause the prop to come out of the water.
You may be able to get away with a long shaft mounted low enough but also figure that you have to have the prop and cavitation plate in the water to start the OB. With the high freeboard of the 25, for the same prop depth the OB motor head will be up higher and easier to reach.
I have not measured the drop of my bracket but would guess it is closer to 10" than 14". To get my prop to clear the water I have to raise the bracket and tilt up the OB. If I had 4" more height I could skip tilting the motor up.
I can't lean over far enough to tilt up the motor without raising the bracket. (Actually I have power tilt so I never raise my bracket anymore)
Think about reaching the shift lever when deciding what to get. When I looked at Tohatsu's last year the shifter was on the front of the OB cowling. Some have the shifter on the tiller just behind the throttle and some have the shifter built in the throttle. Turn one way for forward and the other for reverse.
The closer the shifter the easier life will be.

 

[dwdooher]

Ward,

Very helpful, thanks.

Dan

 

[kpgraci]

When I was researching this the consensus was the longer the better. Prop choice is another thing to consider. The 6hp has a sailing prop option with a 6" pitch vs the std 8" pitch and broader (elephant ear) blades. The prop makes sense for a sailboat boat due hull speed limitations. Not sure if that is available for the 8hp.

 

[korchinskyp]

If you have the original wedge and mounting bracket, you may have a problem with using a four stroke outboard. It's not just the extra weight but the increased torque of the four stroke.

 

[dwdooher]

I removed the orginal wedge and mounting bracket and reinforced on the transom for new 4 stroke and increaesed torques, so that is covered. Problem is I got a long shaft, 20", and come to learn it should have been extra long, 25". I preoviously and a Tnazeer 22 and did not think aobut more vertical on the transom for the Oday 25. l purchased a mounting bracket with only 9 12" vertical drop, so had to put the engine low on transom. The engine sits in the water below the water intake, so that is ok, but the first fin above the water intake is also supposed to be below the water line as well when the boat is just sitting in the slip or anchored. If crew sit back in the cockpit and the engine is running, the weight and torque put the fin below the water line. However, the engine is mounted too low on the tansom and raising lowering is harder than it should be. And really need to get the first fin below the water line so it is mounted correctly. Am loooking at Gaerlick mount with 15 1/2" verticlal drop, so hopefully that will do the trick.

Thanks.

 

[Ward H]

Sounds like you are on the right track with the backing plate and trying a bracket with longer throw. A 25" would still be better in rough conditions as the fin (cavitation plate) needs to stay in the water but if a 20" is what you have, try the bracket first.
One thing for sure, you will benefit from the additional throw no matter which length OB you end up with.