77 O'Day 22 Transom Weight

[ChattOday]

2 questions, actually 1. How study is the transom? I want to add either a lady or small swim platform as well as install a stronger outboard mount, and a heavier outboard. I find my current outboard fine for fair weather but lacking power in any current situation.

I would probably glass in some 1 inch think plywood inside the bilge along the entire length of the rear transom. Do you think this added epoxy/wood strengthening would support the above uses?

The swim platform/ladder is so my small daughter can get on easily. While I make do with those nasty throw over ladders, I doubt she could. I am drawn to a small swim platform as it would be easy to swim up to, get on and then step into cockpit. We also have a dog that could probably be trained how to use as well.


Thoughts? Likely moving up to an 8 or 9 HP motor. Weight anywhere between 85 to 96 pounds. Current 5 HP, 4 stroke is 55. So not a huge increase there.

 

[Brian Schwerdt]

I have been considering a swim platform as well. Please let us know what you end up doing!

 

[jepomer]

The transom has enough strength BUT you do have to spread the bolt forces using plywood (or something similar) backing. The outboard motor mount will give you a good example of what to do. Simply bolting into the fiberglass will not be sufficient — the bolts will pull through. Make sure where you mount the swim platform, it will not interfere with the water flow when heeling.

The larger outboard is acceptable. The brochure says up to 15 hp.

 

[Daydreamer]

I have an 8 hp two stroke that powers my 22 along very well. 6+ knots at 3/4 throttle is no problem. Motor weighs about 65 pounds.

Make sure the core is in good shape behind the motor mount. Take the bolts out and dig around to make sure it is not wet or soft.
My transom does have an extra layer of plywood and glass inside and backing plates for the bolts. There is very little flex in the transom.

I have a small ladder on the port side that works ok. I have looked at the small platforms with a ladder and thought they would be nice. My ladder has 3x6 x1 blocks for backing inside.

Have fun !

 

[Brian S]

Do you have a high thrust propeller on your existing motor? I have found a drastic improvement in power and speed from my 5 hp once I swapped the factory stock speed prop (suitable for aluminum fishing type boat) with a 3 blade, elephant ear, larger diameter, low pitch prop suitable for heavier, displacement hulls. I have better bite on the water at low speeds, putting the motor in reverse at the dock will actually stop the boat going forward, better reversing, and higher engine RPM at WOT allowing faster boat speed through the water - exceeding hull speed and putting out a nice big wake. (Not that a big wake is a goal, but that's what you get going faster in a displacement hull. )

 

[Sunbird22358]

On the swim platform, proper backing plates/block should be strong enough. However, make sure that the platform will not interfere with the swing of the rudder.

 

[ChattOday]

Yes. Garelick actually makes several of the same small sizec platform with different brace support locations to give options with things like motor or rudder swing. The one I am looking at should be OK as the rudder has a larger swing area below water line.

 

[kpgraci]

I think a 8 to 9 hp is overkill. I have a 6hp tohatsu with the high thrust prop and I get hull speed at half throttle, about 4000 rpm (max rpm is 5500). That being said the transom can handle the 85# or so of an 8hp. I think a swim platform is a great idea.

 

[Brian S]

I think a 8 to 9 hp is overkill. I have a 6hp tohatsu with the high thrust prop and I get hull speed at half throttle, about 4000 rpm (max rpm is 5500). That being said the transom can handle the 85# or so of an 8hp. I think a swim platform is a great idea.

Wow, Ken, you get 4K rpm?

My 5hp Nissan 4 stroke used to turn 2160 rpm with the stock prop. I put a high thrust prop on, and my WOT increased to 2340 rpm, a top end speed increase to about 6.3 knots, and with some big stern waves following me - definitely pushing past hull speed. Sure, a 22 has more waterline length, and faster hull speed, but I can't imagine it going fast enough to get my motor up to 4K.

Also, I have idle set to 750 rpm under load.

Sometimes I wonder if this little motor has some problems or not, but it's very reliable, so, I just keep keepin' on...

 

[kpgraci]

Yeah, 4000 is max, 3500 gets me to about 5.5 knots. Hull speed is 6.3, to push it that far you get diminishing returns and I can tell the motor is working hard so I don't like doing it. The high thrust prop is a 6 inch pitch I believe, I had calculated to get full rpm, hence full horse power, I would need a 3 or 4inch pitch, which is kind of ridiculous. All I can figure on the difference is I weight about 2300 lbs loaded and I assume I have more wetted surface, but my waterline is 19 ft.