Oday 25 Engine mount angle on transom

[ddooher]

My ODay 25 had a 6 HP mounted on the original angled block on the port starboard. I moved up to a 8 HP. I had the transom reinforced with plywood and fiberglass on the inside, so it bears the heavier engine.

I put a new block on the transom, but did not realize it had to be angled. It holds the engine fine, but without the angle, the engine shaft is always tilted back slightly instead of straight. Does anyone know what the angle should be on the bock where I attach the bracket. I had heard 13 degrees. Anyone know if D&R Marine, or another outfit, sells an angled block. Thanks.

 

[Erieau]

I made a new block for a bigger engine too. Here's how I did it:

Holding a 12" spirit level against the transom, I rotated the top of the level away from the transom until it read dead-vertical. Then I measured the distance (using my third hand) from the top of the level, to the transom. Bingo. All the measurements you need to make an angle template out of cereal-box cardboard.
The finished angle block needn't be perfectly vertical ("you're not building a damn piano," as Dad used to say), as there is some angle adjustment on the outboard too.
Best of luck.

 

[dwdooher]

I made a new block for a bigger engine too. Here's how I did it:

Holding a 12" spirit level against the transom, I rotated the top of the level away from the transom until it read dead-vertical. Then I measured the distance (using my third hand) from the top of the level, to the transom. Bingo. All the measurements you need to make an angle template out of cereal-box cardboard.
The finished angle block needn't be perfectly vertical ("you're not building a damn piano," as Dad used to say), as there is some angle adjustment on the outboard too.
Best of luck.

Good advice from dad. Makes sense. I have a spirit level and understand rotating the top of the level away from the transom, but am having trouble picturing what you mean by the level reading dead vertical. I got a C in Geometry and a B in Trig. Thanks.

 

[Erieau]

At the ends of your spirit level are the "vertical" bubbles. In the middle is the bubble for levelling horizontally. You're interested in the vertical one.
Dead vertical means the "vertical" bubble is in the middle of its tube.
Crude drawing follows:

 

[dwdooher]

At the ends of your spirit level are the "vertical" bubbles. In the middle is the bubble for levelling horizontally. You're interested in the vertical one.
Dead vertical means the "vertical" bubble is in the middle of its tube.
Crude drawing follows:

Thanks a million. I thought it was something like that, using with the bubble at the end of the spirit level to find dead vertical. And thanks for the high-tech diagram.

 

[Ward H]

dw,
Just to cover all bases, have you checked if the OB has a trim adjustment? I have only used three outboards but they all had a trim adjustment. It was a series of holes with a bolt through one set. You pull the bolt out and can set the trim/tilt, then put the bolt back in.
Here is a photo on a Yamaha OB. (photo is sideways)
I also don't think the trim of an OB matters as much on a sailboat as on a planning boat. I'm lucky enough to have power trim and have not see much difference in different trim positions.

 

[dwdooher]

Good question. I adjusted the trim as far down as possible and there is still a tilt. The cavitaiton plate was never under the water line, even with the bracket set at its lowest postion and the trim all the way down. The water intake was under the water line, so that was ok.

I did not know what was causing the problem that the cavitation plate was not below the waterline, that I had not used the wedge to mount the bracket on the transom to ensure proer tilt, until a contractor explained it to me. The only way it would get under the water line was if two people sat aft in the cockpit. But then I was always adjusting the bracket up and down due to any wakes that brought the outboard out of the water, including the water intake. Took a walk around the docks and realized all the transoms had a wedge to ensure good trim.

Will admit that all of this could have been avoided if I had read, and made sure I understood, the owner's manual (Nissan 8 HP 4-stroke) and bracket (Gaerlick) instructions cautions on tilt. I also have a long shaft instead of extra long. My last boat was a Tanzer 22, with a lot less transom to cover, and long shaft was fine. It should work out ok on the Oday, as I have also gone from a 9 1/2" vertical drop bracket to the longest vertical bracket, 14 1/2", Gaerlick makes. Longer story, but at least was able to get the longer bracket, very expensive, for a trade-in on a gennny. Lot of lessons learned on this one.

As usual, the forum thread has been a huge help. Thanks.

 

[Ward H]

Yep, the 25 has a lot of freeboard which really needs a XL shaft to keep the prop in the water while the head unit is high enough to reach.
While changing the angle of the block may get the motor vertical, I doubt that it will move the cavitation plate deep enough into avoid cavitation in wakes and small waves.
You might want to consider how mine is set up to allow you to mount the OB bracket a little lower.
On my 25 the original owner took off the block and had starboard plates bolted on both sides of the transom to reinforce it. Then he bolted the bracket direct to the transom. The bracket has some tilt adjustment and with the OB tilt adjustment the motor was vertical.
The bracket pushes the OB out from the transom far enough the OB can be tilted all the way back.
I've posted photos of how mine is set up in some other threads but can repost if you are interested.

 

[dwdooher]

If you could re-post photos, that would would be great. I took off the original angled block, it was on port, as well and reinforced so I could put on the 8HP 4-stroke. Never thought to save it to replicate the angle. The current block is very low, and the contractor said it could go even lower, which surprised me. Between the angled block I will be putting on and the longer vertical drop, hopefully that will do the trick. Extra long shft is not in the budget. Thanks.

Dan

 

[Ward H]

Here are some photos of my outboard and how it is mounted.

The first photo shows it tilted all the way down. The OB that was on the boat when I bought it was adjusted to make it vertical. I was lucky enough to get an OB with power tilt so I just adjust it to vertical each time I tilt it down. That is shown in the last photo, which is a bit blurry.

The second photo shows the inside backing plate. If I was doing it myself, I would have used 3/4 ply sealed with epoxy instead of the starboard as a backing plate but this works. So far there is no sign of the transom flexing, despite a run in with a dock last year which was hard enough to crack the cowling on the less than year old OB.

This was probably done in 2001 since that was the year of the OB on the boat when I bought it. Coincidently, I saw another 25 O'day at our marina sitting on a trailer, which had the same set up using the flat starboard and OMC mount. That was a Sandy damaged boat the marina bought for parts.

The bracket is an OMC which I understand is no longer made. I think it could have been mounted a few inches higher because when the bracket is raised the prop is still half in the water but that is not worth moving it now.

While some OBs may need the hump to move it out far enough to tilt back without hitting the transom, I think it is up to the bracket whether it is needed.

BTW, that's a Yamaha T9.9.