Twin Suzuki 60s on CD22

[jingram]

[Matt Gurnsey]

Most dealers will live with a 5% rule- 115 + 5% = 121

We have done twin E-Tec 60's on a 22. Same weight as the 40/50 so we felt okay with it. The 60 Suzi is lighter and a smoother at idle, so we would be willing to do it.

The question becomes do you need it? Well, it's your money. It's about $500 more per engine to go from 50 to 60, all the other rigging costs would be the same.

I don't think you'll see any improvement to low end torque, most of that extra horsepower comes at the higher end. You might get an extra step in pitch on the props with the 60's, but that might hurst hole shot ratrher than improve it.

In the end, you pays your money and you makes your choices.

[bridma]

I'm a newbie so my thoughts don't count for much. I like my 40s, plenty of speed for me. I putter along most of the time at 6/7 mph, go up on a plane now and again to give the engines a run, and then go back down again. Up on plane requires a lot more concentration watching out for deadheads, crab/shrimp floats and any other garbage in the water. Apart from the serious fishermen among us needing the speed to get to their fishing grounds, what's the hurry?

Martin.

[joeC]

Guys
I bought twin 60s almost a year ago and love them. I get better fuel burn
then with the single Honda 90 carbed and the boat handels better. I normally cruise about 20 to 21 and the twins are turning about 4150 rpm.
The boat will go into the unsafe zone has far has speed I have seen 38mph on the garmin gps but to fast. Best thing is with 3 aboard it will plain on 1 motor and run about 13mph
Joe

[Sunbeam]

[Matt Gurnsey]

Running one of the 60's may get the boat on plane, but by definition you would be lugging it. propped for twin application, the motor would not be able to get to the recomended WOT as it will be doing twice the work it normally does.

In an emergency- fine. Normal use, run both engines.

[jkidd]

[Matt Gurnsey]

At displacement speeds you'd be fine on one. You'll be running under 1500 RPM I imagine, so it shouldn't be an issue.

[thataway]

I don't know if you can document that there were major structural changes to the transom to account for a larger engine thru time. Most builders will put in a knee, beef up the splash well, put in a heavier core or even change the hull forum to account for more hp. Unfortunately many small boats are not designed by a NA--not that that is always necessary, but it is certainly desirable to have a NA or yacht designer involved. Often increase in hp is requested by the customer, and the factory says "why not--if we sell more boats OK". It is not just weight, it is also the force put on the transom.

Joe C states that the boat goes into an unsafe zone at 38 mph--from my experience with C Dories (and other similar boats) I would agree that handling and safety would be compromised by going that speed. As I have stated many times, my feeling is that the boat becomes a bit unstable at about 30 knots. Why take a risk that someone will take the boat beyond its safe handling speed.

I can see the argument if you were going to be running the engine at high elevation, and felt that the 100 hp would not be enough to get to a decent cruising speed.

Jingram, I apologize if you took my post to be "too stern or almost a bit indignant". However, I have spent much of my life involved with boating safety, and I see a lot of people who do not have the knowledge of boats who do things which are not wise. I invite you to describe to us your boating experience, and experience in these types of boats.

I also agree on the issue of lugging a 60 trying to plane the boat. (especially with any load). I examined a Pensacola boat for two potential buyers which had a Honda 50 on it, and the owner could not get that boat to regularly exceed 12 to 13 mph, so he ran it at displacement speed. I would never buy a boat just because 10 hp more "might" plane the boat in case of a lost one of two motors. Again, modern outboards are so reliable that it is very rare to have a failure, unless it is contaminated fuel or lack of electrical power.

There are reasons that a new Suzuki may bet better mileage than a carbureted outboard. Part is the injector system and the lean burn system. I am sold on Suzuki outboards.

As I said, it is your money and your boat--do what you want. You have both sides of the argument.

[jingram]

Bob again, not sure why I sense so much hostility from you about this. You are right, it is my money and I will do what I want. That being said, just so we are clear, the question originally posted wasn't as to the merits/detriments of dual 60s, it was whether it was even doable from a legal/dealer perspective.

As it is, I appreciate the input and the ensuing discussion the thread started. It was great to hear pros and cons and to understand various people's experiences. That being said, I didn't really sense any hostility except from you. Just because people are debating the merits of something on this forum and "questioning" what may be the status quo, doesn't make it a bad thing. After all, if that was the case, you would all be running 70hp singles on the 22 eh.

I never once said I was looking to go "fast" or that I was "bent" on 60s. If anything my thinking was that I might be able to run at slightly lower RPMs and increase fuel economy as a result AND that I might be able to get on plane a bit easier on a single 60 than a single 40. Clearly I will be lugging the motor if I do this, but this is a function of prop more than anything else. Correct?

As for the force on the transom... I would argue that would be torque dependent more than anything else regardless of how much horsepower you are running. In fact, a big torquey 115 two stroke could put far more stress on the transom I would think than twin 60 4 strokes with lower overall torque numbers. Am I crazy for thinking that?

The wonderful thing about this thread is that we were able to discuss this and talk about both sides instead of it just being a "go with twin 40s and be done with it" thread because that is what WE have and we said so. I don't find those threads very constructive. Maybe I'm in the minority though.

The input provided from EVERYBODY, including you, has been very much appreciated. Thanks for sort of bench racing with me and debating the pros and cons. It was really helpful and hopefully if/when this comes up again in the future, it will be equally helpful then.

Cheers!

[chimoii]

Jingram, many thanks indeed for a very thought provoking topic. Translate torque into thrust and you paint a good picture.

If you have more torque available then you have more thrust and more strain. Indeed, one could make an argument that distributing the thrust between two mounting locations, neither of which is at the boat centreline may actually reduce localised strain. I've seen that result where twin 1200hp gas turbines produced less strain than a single 2300. We will probably never know in this case because I doubt that anyone will ever do an FEA or strain gauge a CD22 transom and so do controlled testing.

Hammering the throttle(s) will obviously put much more strain on a transom, regardless of the type of propulsion. Operator input will be a big factor in assessing transom integrity over time.

Matt's rule of thumb is probably a good one and his other comments make a lot of sense. Once again, thanks for stirring the gray matter. After 40 years + working with propulsion systems I still love to discuss these things.

[joeC]

Guys
My boat is an 06 model and with the twins will run a hundred miles on each tank. Know this because the boat goes in the gulf anytime it is calm
and my trip speedo. In rough water on the river that I live on the twins deal with crossing ski boat wakes much better also maneuvering around the dock much better. Offshore we troll on 1 much better fuel burn. My last statement I think the boat is dangerous at 24 25 mph 38 mph is
crazy but it will do it maybe more. Honda quit 1 time hade to run back 30 miles on the Tohatsu 6hp kicker never again
Joe

[Will-C]

If more is better how about a pair of Yamaha 70's they only add another 28 pounds each? I'd be careful with Bob as he is a valuable resource. I reread his replies I did not see any hostility but that's just JMHO. Certain things are probably better left unsaid if you want the best out of this forum. Good Luck with your choices.
D.D.

[ghone]

Hi jingram, i'm not seeing Bob as hostile on this one, he has a lot , I mean a lot of time on the water and been there done that. He just wants us all to be safe and not get into a corner where we can't get out of. It used to be 70 hp was all folks fitted on the cd22 as we go along, we get more stuff and more neccesaties and hence need more power. I just looked at QT in the Harbour here yesterday, visitors from Florida. They are cruising thru and his waterline forward is a good 4 inches visible. How the heck do they do that? That is the factory waterline which hasn't been changed in the mold for years I bet. I have been full time aboard my boat a lot and I had to raise my waterline 3 inches from factory and change my prop. I have full time liveaboard stuff for 2 aboard. My 90 still pushes all that at 25 knots in flat conditions. Halcyon has some 24000 cruising miles on twin 40's and is still cruising. Twin 60's I am sure as kitsap marine said are do able and you will probably never go wot. I lean toward it being a bit experimental and may be a challenge come resale time. Best of luck on your new boat. George

[dutch123]

Hello jingram, did you know a chevy 350 will fit in a cavalier if you use a shoe horn? With the right gearing it may even get good fuel economy. Could you do it yes, should you no! Thataways advice and comments are said for good reason because he knows better than most. You asked the question, be prepared for the answer. Redfox has been using the new Yamaha 70 with great success for quite some time and others with 80 hp including myself have more than enough power. Remember that the 22 was designed for 75 hp.