Jack Plate For A 1981 13 Sport

[Jefecinco]

I'm considering adding a jack plate to my wife's 13 Sport this Winter and would appreciate some advice on the subject.

I want to be able to adjust the engine mounting to allow the tilt and trim unit to tilt the engine completely out of the water when moored. I believe it could be possible to do this if the engine could be mounted so it is vertical when trimmed fully down because the transom of the 13 is raked several degrees. I could try to do this with a pair of wedges sandwiched between the transom and the tilt and trim assembly but don't want to try this without some assurance of success. The engine can now be tilted up enough so that only the forward half of the nosecone is under water.

The transom is curved which causes the mounting brackets of the tilt and trim unit to be in a bind. This does not interfere with operation but can't be good for the unit as it is always stressed. This could be corrected with the right wedges, but again, I don't want to try it without success.

The engine is an F30ELPT (30 HP Mercury four stroke with electronic fuel injection and tilt and trim).

Bob's Machine Shop advertises a Convertible (sic) MJ5 2.5 or 5 inch setback manual jack plate (item# 100-205000) for about $260 and a bolt kit for $35.

Is a jack plate the right approach or is there a better solution?

[flymo]

Butch, I'm not completely clear about the binding you're referring to - is the transom curve preventing the motor from tilting up all the way?

Regarding getting the motor to tilt more, I'm sure you've already checked to see if there is some type of adjustment to let it come up higher, but if not, that would be a first step. I did a quick search and came across the following transom wedges http://thmarine.com/th-marine-products/outboard-performance/outboard-transom-wedges - the CMC wedges seem like a potential solution to getting more tilt, but would need to be customized to help with the binding.

Another option is to just live with it as is - having the nosecone in the water does not really hurt anything.

[Jefecinco]

flymo,

Thanks for the find. The reverse wedges look like they could get the job done. The binding isn't a real problem, just something that's not quite right and therefore offensive to my [rigorous] view of things mechanical. The only time it has been a problem was when I decided to replace the badly corroded trim cylinder mounting pin and could not remove it no matter how much I banged on it. It was finally removed by cutting it in half with a carefully used sawsall. When installing the replacement pin with new bushings I found it could not be done. I then realized if I loosened the engine mounting bolts on one side it would allow the pin to be installed. I had to back off the mounting bolts about a half inch to make it work.

A positive aspect of the wedges is that they would not affect the steering cable or the fit of the built-in engine cover on the boat cover.

The problem doesn't restrict the range of trim and tilt. I looked into an adjustment of the trim limit switches (if there are any) but could not find anything.

Several years ago I looked into adding weight forward to raise the transom when moored but after adding 120 pounds ahead of the forward thwart without success I abandoned the idea.

[jimh]

Re the curved transom on a 13-foot Boston Whaler: CETACEA Page 56 showed how shims were made to make the transom become flat for mounting a modern outboard engine.

[Jefecinco]

Jim,

Thank you for that excellent reference. I believe I may have seen it many years ago and that is probably where I got the idea of using wedges.

I noticed from Carl's photographs that the engine in the article was raised about four or five inches higher than mine. That would certainly get my lower unit clear of the water. I wonder if I could get away with using King Starboard rather than the Plexiglas in the article. As the stock I have is white it would look better without the use of caulking.

I'm going to try to locate some CMC Vertical Extensions as I like the way they look vs the T&H Reverse Transom Wedges.

I have no idea how to shape the wedges but perhaps a table saw with the table tilted to whatever angle is required would be the tool to use. My neighbor has a table saw so if that would work I can probably get it done.

[flymo]

Butch, the reason Carl's motor is raised is that his 1962 model has a transom set up for a motor with a 15" shaft, and he is using a motor with a 20" shaft. Both your transom and your motor are 20" so you don't need or want the lift.

It's certainly very reasonable to make the wedges out of Starboard - you don't need anything more than that, if you want to do it yourself. The challenge is going to be getting the angle right in both dimensions. You'll also want to keep the piece as thin as possible overall; moving the motor back will push the stern down and put more of the nosecone in the water (it's for that reason that I am not advocating a jack plate either).

Doing a double-taper cut on a tablesaw is possible, using a taper jig and tilting the blade, but it's probably going to take some trial and error. You might want to practice on some scrap wood first. Also note that this type of cut on a table saw is potentially dangerous, so plan each step, use push sticks, and stay out of path of the blade.

Tim

[Jefecinco]

Thanks, Tim. I wouldn't dream of using a table saw for more than simple ripping which is all I've used one for. My neighbor will have to be convinced to do the work for me. As to raising the engine, I believe there may be one more hole left in the engine for adjustment. It's been raining here for several days so I have not taken a look.

[Binkster]

I built my own jack plate with a 6-inch setback for my 1961 13-footer with a 15-inch transom, and I'm running a short shaft (15-inch shaft) 2008 Mercury 25-HP FOURSTROKE. The engine is raised about 2 to 2-1/2" above the top of the transom. The cavitation plate rides on the surface when the boat is planing. Also, the entire interior is moved forward 6-inches. With these modifications the boat takes on an entirely different personality. It ride like a bigger boat with non of the bad manners usually associated with 13-foot Boston Whaler boats. I can't tell you if, when tilted up, the entire lower unit clears the water, as I never tilt it up. In this motor--unlike the 30hp version--the tilt n trim is not available, but then I don't have the additional weight. I leave the tilt pin set in the next-to-last pin hole for running, trailering and launching the boat. Never had a problem.

A 6-inch set back jack plate will help any 13-footer.

rich

[Jefecinco]

Thanks to all for all the good advice and information in this thread. The reverse wedges recommended by flymo have been installed. They are such a good fit that they are unnoticeable. Thanks again, flymo.

I doubt the boat will be in the water before February and perhaps March but I suspect the original goal will be met and I'll know as soon as we launch. It remains to be seen if hole shot will be degraded by the more positive angle of the engine when fully down. I suspect not, but if that happens another propeller may take care of it. I'll report back when I know more.

[CarlRobert]

Gee whiz, it's been a long time since I last posted! Thanks, jimh, for continuing this outstanding resource.

My 1962 Sport 13 profiled on Cetacea page 56 is still in use. The vertical extensions and wedges have held up perfectly over the years and the boat has seen a lot of use in both the Pacific, California Delta and local SF Bay Area waterways. In fact, I have not even had to redo any portion of the work, a testament to 3M products and luck. The motor is solid and runs great.

My two sons, now young adults, use the boat for fishing and to create their own adventures, and I, at the urging of my wife, took the plunge and bought a 2015 Montauk 190. What a ride! I told the boys that whoever gets their own driveway first gets the Sport 13.

I plan to post pictures of the two Whalers in a side by side comparison once the rains stop as the differences between these two boats is quite striking, in my opinion.

Whalers are simply the best.

Thanks again, jimh.

CarlRobert

[Jefecinco]

CarlRobert,

It's interesting that you have both a Sport 13 and a 190 Montauk. We also have that combination though our 190 is a bit older and our 13 is a bit newer. As you may have read our 13 now also has engine wedges installed. Although the 190 isn't a large boat the 13 looks tiny in comparison. We love both boats but my wife certainly prefers the 13. I'm not sure I disagree with her preference. It's certainly a very handy little boat. It's very easy to manage at the launch ramp, goes where the 190 can't to include slipping under low bridges into sweet fishing spots, sips fuel and cleans up quickly. However, when even a slight chop is prevalent the 190 is my preference.

[Jefecinco]

UPDATE: I've finally launched the boat and had it in the water for a few days. I' delighted to report the entire lower end and propeller are clear of the water when the engine is tilted out fully. The reverse wedges worked. I'm grateful for this suggested low cost solution.

[jimh]

Gee whiz, it's been a long time since I last posted! Thanks, jimh, for continuing this outstanding resource....

Whoa--I just came back to this thread. Hello to Carl after a long time. I'm glad to hear your fine 13-footer is still in the family. Thanks for the kind words about the website.