Transom Riser for a 22 cruiser?

Kushtaka

New member
Has anyone ever tried to use a 25" shaft (xl) outboard on a 22 cruiser by building a transom riser?

I envision an aluminum structure that fills the transom 5" high, maintaining the width of the transom, and overlaying the transom on both sides.

I'm a big fan of overkill (someday ill post the windlass backed I had made and the process I went through to drain my anchor locker) and so would want to extend the riser to the bottom on the outside.

I like the idea of my motor being a little higher. I was planning to get rid of my spring loaded kicker mount on my port corner ( a death trap!) and move it amidships next to my main an tie the steering together. The mini jacker would get the kicker out far enough to clear the trim tabs, but if I had the riser build, I could extend it to the sides and weld a kicker mount to the transom that allows my kicker to tie in steering and cleaner the tabs. I could also put my transducer on there and have no more holes below my waterline except the lower motor bolts.

I wonder if I could reuse the same lower bolt holes?

I wonder if there would be major performance or handling issues?

I wonder if anyone else has done this?

I wonder if anyone has ideas to improve, warnings I should heed, lessons earned, or experience to share.

I live in a commercial fishing town, and know for a fact that anything can be done to a boat. That much I'm sure of. Whether it should be done or not, that's another matter entirely.
 
I'm a bit confused as to the "why?" part of this modification. What do you hope to gain by raising the motor and going with a longer shaft? At first glance to me, this seems to be a net gain of nothing at considerable expense. What am I missing?
 
Our 22's are sensitive to weight on the stern. I suspect you'll just create problems with your efforts to fix a non existent issue.
 
The why is a good deal on the wrong motor.

Someday I'd like to put a bracket on it and enclose the transom, and I'd Ike to think that day is within the life of my next outboard. If I did that I'd want a 25 if not a 30.
 
Curious as to why you would want to use an XL shaft engine on a 22. Perhaps, if you already owned a XL shaft motor or a lead on a low priced one it would make sense.

I had an Arima previously and it had twin 45 Honda's. I preferred a Kicker and Main combo. In my search for a longshaft motor I came across a great deal on a newer XL Yamaha motor. I purchased it and installed a jackplate to get the height right. This raised effectively raised the engine height (cowling) and pushed the weight a bit further back.

The combination while not conventional, worked really well. Loved the motor.
 
Curious as to why you would want to use an XL shaft engine on a 22. Perhaps, if you already owned a XL shaft motor or a lead on a low priced one it would make sense.

I had an Arima previously and it had twin 45 Honda's. I preferred a Kicker and Main combo. In my search for a longshaft motor I came across a great deal on a newer XL Yamaha motor. I purchased it and installed a jackplate to get the height right. This raised effectively raised the engine height (cowling) and pushed the weight a bit further back.

The combination while not conventional, worked really well. Loved the motor.
 
Can it be done, yes. What will you gain--other than putting a different stress on the transom? Getting the motor head higher, will decrease the stability to some degree. The aesthetics are not good--but I have seen this sort of thing done in AK….

Swamping the motor is not a problem on the C Dory--they lift very rapidly. If you did take a wave over the transom--then it would have a lot more water, and be close or over the top of the splash well. Even with an enclosed transom, and putting a transom extension/pod on the transom to support the motor--you probably would stay with the standard shaft length…

I don't see it as a good idea.
 
You should be able to swap out the leg of the motor (between the power head and the lower unit). It'll cost a few hundred bucks, but can be done fairly easily. On my RIB I used to own, I is was going to swap the leg on the Yamaha engine I had for the very same reason, but once I figured the cost, it was a lot cheaper in the case of that boat to build something to lift the engine up a couple of inches.

What you seem to be planning for your CD will probably be a wash as far as the cost goes compared to fixing the engine. The pain and hassle of modifying the boat versus changing the engine will probably be a lot worse.
 
It's not just the leg that needs to be swapped out but that plus the drive shaft and shift shaft. Maybe you could get those along with the shorter leg. I also see no advantage to raising the height of the transom just for an XL engine!

Charlie
 
ssobol":2693dt3j said:
You should be able to swap out the leg of the motor (between the power head and the lower unit). It'll cost a few hundred bucks, but can be done fairly easily. On my RIB I used to own, I is was going to swap the leg on the Yamaha engine I had for the very same reason, but once I figured the cost, it was a lot cheaper in the case of that boat to build something to lift the engine up a couple of inches.

What you seem to be planning for your CD will probably be a wash as far as the cost goes compared to fixing the engine. The pain and hassle of modifying the boat versus changing the engine will probably be a lot worse.

I looked into this a few years back when I was considering options and it was around $1000 to do the swap to a shorter leg on a Yamaha F115.

Perhaps if you found a good price on the shorter leg and were able to perform the changeover yourself you could save some money. Also, you could re-sell the longer leg and recoup some of the $$$.
 
After you've paid a marine engineer for stress analysis and done some mockups to see how the thing will look and then made the change, you'll have spent a lot more money than getting a shorter shaft motor. I'm sure that the parts for a short shaft version of whatever motor you have that is driving you to such thoughts are available at reasonable cost relative to what you are proposing.

Also, think carefully through the whole re-sale issue. Lots of people on this board have expressed their unending love for their C-Dory only to be putting it up for sale a year or two or even a few months later.

A cobbled together mod, even if working well on a finely engineered boat like a C-Dory will knock a big hole in your resale value, almost guaranteed.
 
Thanks for the warnings. I hear you.

But, onward I go. I've done very well doing things people said I couldn't or shouldn't when they make good sense to me and nobody else.

So, has anyone actually run a lifted 25" shaft outboard on your 22?

If so, can you comment on:

Performance?
Handling?
Experiences?
 
Oh man!

So is is exactly what I want to do:

http://www.c-brats.com/modules.php?set_ ... php&page=2

And I'd guess is is e boat Dr. Bob was referring to when he said he'd seen things like this done in Alaska.

AND, this boat was for sale about a year before I was ready to move on to a CD22, AND it was for sale in ALASKA!!! :cry

Who were the owners? Anyone know who owns it now? I'd love to talk to them. I wouldn't close in the transom though. I'd open it up and put a seat across, and maybe a sissy door through to the bracket.

Now I'm thinking I'd just skip the whole riser,many go for this. I love it!
 
The most important thing to get from the other experimenter will be his structural analysis. If he has had that done by a marine engineer, it will be invaluable for you as you press forward. If he has done the TLAR method of engineering, you would need to be cautious about copying his design. (That Looks About Right).

Good luck, we will be excited to follow your progress though I'd not do that mod to my boat.
 
He is using the standard long shaft--not the extra long.

The splash well seal up and bracket is a fairly common modification. (not especially in C Dorys). Also some remove the splash well, and put a solid transom, then the transom extension. If I was younger and that would fit what I wanted, I would not be hesitant to do that type of modificaion--I would probably want one of the early boats prior to 1987.

No what I had seen was in Wrangel and it was a Bayliner, 23/24, where the engine was removed. The cockpit, and transom were covered with Al diamond plate, and then an extension was done using an extra long shaft outboard to power the boat…Welded up out of Diamond Plate. It was floating--but a little low in the water. I probably have a Kodachrome slide of this somewhere.

I have seen others similar--but not on a C Dory.
 
Is a fairly common mod around here, but more frequently seen when an inboard is converted to outboard. This I withe final goal for me. A transom riser would be a stopgap solution to use the new outboard. One of the best things about offshore brackets is getting the motor up higher. While I don't expect I'll be getting the outboard I had originally started this thread with, I might still want to go 5" up. We shall see. In the end, there's nothing wrong with my motor and it's been well maintained.

My hull is a 1993, so still pre mass-production, but post thick transoms.

Lets go back t the reasons for this mod. I love many things about my boat, but the cockpit space is not one of them. There is a lot of space taken up by the splashwell and lazarettes. I'd like to take those out and have more deck space. I could take out the fuel tanks and put in saddle tanks, and then have more space. Not sure she I'd out the batteries, but maybe under the v berth to offset some port weight. I also carry 630' of rode (30' of it chain) up front, and with my boat set this way, does not drain water to the stern with full tanks. Plus that weight distribution aft can be offset by bracket buoyancy.

Point taken about THAL engineering, but the proof is in the pudding. A broken clock is still right twice a day.
 
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