Repowering

[Tacklewasher]

Haven't been around for a while.<br /><br />Anyway, I have a 1975ish 18' Starcraft Aluminum boat with an OMC Stringer drive (140HP drive but 120 HP motor) and it needs either rebuilding or replacing.<br /><br />I don't like this motor/drive combo. The upper leg leaks and I can't get it sealed. The lower leg is fine but the damn lift is flakey. Plus I can't lift it when close to shore, or drive in shallow water etc. I use this boat mostly for fishing but it did not see water last year as the motor is not running.The the motor has never really been set up right (has a lot of auto stuff on it etc.) and the motor also needs a rebuild.<br /><br />I want to repower but am not sure the best solution.<br /><br />Option 1 is to pull the motor and rebuild it. Put it back in and try to live with it.<br /><br />Option 2 is to get a Merc motor/leg used. I'd have to fill the hole in the transon as the OMC uses the big rubber ring (which has a small leak). Not too big a deal as it is aluminum. I'd try to get 160 HP.<br /><br />Option 3 is to pull the drive and replace it with an outboard. For my use, this seems like the best option. It would let me lift the motor, cut the weight down, give me more room in the boat but would mean building a well for the outboard and making the transom stronger. Again, be looking around 150HP.<br /><br />So, is option 3 doable? I figurre it is possible as I'm playing with alum and not fibreglass. I'm never going to be happy with the leg I have and I think and outboard will be cheaper than a I/O.<br /><br />What might I be missing?

 

[Solittle]

Re: Repowering

Me thinks your thinkin option 3 (outboard) is good thinkin. I have had one I/O that was always needing something and a slug of OBs. Years back I had an 18' Starcraft with a 1966 100 hp Johnson on it and it flew. Give some thought to a V4 rather than a V6 unless speed is at the top of your list. In either case check the weights before you commit. iboats has a bunch here:<br /><br /> http://www.boatmotors.com/rebuilt_outboard_motors/

 

[Tacklewasher]

Re: Repowering

So, I received a comment elsewhere that the transom on these boats (with the stringer drive) is not strong enough to support a merc style I/O or an outboard. Does this make sense?<br /><br />Given the boats design, I think this can be overcome once the motor is pulled.<br /><br />I need to see a similar boat with an outboard to look at the transom.

 

[Northern Eclipse]

Re: Repowering

I would not worry about the transom being strong enough, since it would need to be reworked or replaced anyway whether you decide i/o or o/b it could be beefed up at that time, The concern I would have is the expense to do so. I have one suggestion,Since the boat is 1975 you might try your luck seeking out another Starcraft from a marine salvage or sitting in some ones field that was set up for o/b or a Merc I/O and cut the back off and graft it on to your boat.

 

[f_inscreenname]

Re: Repowering

Have to love your enthusiasm for that old of a boat. <br /> The cheapest by a long shot is to fix what you have or option 1. No matter what the problems are <br /> As for option 2. If you go with this, after you put a new transom in the sky is the limit. Any Merc/motor combo you want (big block V-8 to a 4 banger) or can find and afford. But then comes you either buy new (BIG BUCKS) or you find a used combo and take your chances on what you get. You may end up doing a total rebuild anyway. Then there is all the trim pumps, gimble housing and stuff that goes with the drive, etc. More money. The easiest and cheapest way is to take it all out of another boat and do a rebuild before installing it unless you are sure it all works right. <br />Then there is 3. You have to gave consideration to that you are taking weight out of one area (where the motor is now) of the boat and placing it in another location (hanging off the transom). Could be a balance issue. You will have to rebuild the transom and build in such a way to support the motor (should also have a splash well) or a least a outboard transom bracket (that would be the easiest but more money). You also have to buy a outboard (not cheap) all the trim stuff for it and controls. Again you can buy this used but when outboard have problems they can get real expensive quick. You will also have to rebuild the interior and deck. Are you sure you want to put that kind of money into a 1975 fishing boat?

 

[Tacklewasher]

Re: Repowering

Trouble is, this leg is not that reliable or useful. Not being able to drive with the leg up has been a pain, and fixing the leak in the upper leg seems expensive. I'd like to go to a more reliable drive and I'm still thinking of the room I'd gain with an outboard. <br /><br />If I'm going to put money into it, I want to end up with something reliable.<br /><br />Thinking about the GilBracket, I doubt I will go that way. Thinking about how I would trailer it, I don't like what the implications are. THat much weight that far back from the transom seems like a bad idea. But I have the room to build a decent splash well.

 

[NYMINUTE]

Re: Repowering

Compare costs and check for newer used vessels. May be cost effective to move up to a newer model. Hell you deserve it! Don't You.

 

[Tom2697]

Re: Repowering

"Some people will never understand the love we have for our old toys."<br /><br />Since you are talking about repairing aluminum I will assume that you are capable of welding aluminum. With this being the case, I would go for the outboard. Also, take Solittle's advice and go for a smaller outboard. A 135 or 140 V4 will perform great on that thing because, with the weight savings of an outboard over an I/O, less power is needed. <br /><br />Last point, the cost of repowering an outboard is comparable to repowering an I/O when you have to replace the entire engine and drive unit as Tacklewasher is saying. Going from an OMC to a Merc will not allow many parts to be reused...and replacing with used parts from someone else's junk is not always the best bet either...<br /><br />One thing I forgot: make certain that the rest of the boat is in good shape where you don't need to rebuild the entire thing (eg - fuel tank replacement, electrical gremlins, etc). If that is the case, take the other member's advise and look for a new boat! You'll save yourself A LOT of time, money, headaches, and sleepless nights...

 

[Tacklewasher]

Re: Repowering

The boat itself is in good shape. The floor is weak in a couple spots but a couple sheets of wood will cure that. It has one rivet that leaks and needs attention. Otherwise it is exactly the boat I want. Fuel tank is fine and I'll pretty much have to re-do the electrical anyway whether I go outboard or Merc I/O. It has decent seats and a nice top plus I can launch it in the local lakes pretty easily.<br /><br />I don't think welding will be needed. The whole back is riveted and I'll continue that way.

 

[Tacklewasher]

Re: Repowering

So, this looks like it is going to happen (i.e. I have the cash).<br /><br />I have a line on a 140 motor with all controls, trim etc. that I'm going to take a look at. My plan is to remove the leg, remove the back (drilling out the rivets) and pulling the motor. It looks like I can do this for under $4K Cdn and end up with exactly the boat I want for river/lake fishing.<br /><br />So, the problems I think I am going to have are:<br /><br />1. Steering. I doubt the steering is the same cable set up. I assume it should be hydraulic.<br /><br />2. Guages. Can you use older guages set up for an I/O with a outboard?<br /><br />3. Transom strength. I know I can fab up a transom to fit, but what suggestions would you have for making it strong enough to support a motor. I'm thinking some hardwood on the bottom of the boat tied into some board running towards the bow a couple of feet. Thick Marine grade plywood sitting on the wood and supports to the end of the other boards (if that make sense). I figure I need to support it vertically as well as in the direction of the bow to prevent it twisting. Still going to be way lighter then what I have. If I tie into where the old motor sat, it should be plenty strong.<br /><br />4.Time. WHo wants to come do this for me

 

[Tacklewasher]

Re: Repowering

Does anyone have experience with the GilBrackets? This looks like a simpler solution, except that it does move the weight further back and may make trailering a bit harder.

 

[jtexas]

Re: Repowering

This might help:<br />I/O conversion to outboard topic with pictures<br /><br />what are you going to do with the extra room you've created in your boat?

 

[Tacklewasher]

Re: Repowering

Thought I'd put the link to the pictures here<br /><br /> http://home.comcast.net/~badgerxxx/Transom.htm <br /><br />Found out the GilBracket is not recommended for under 22 feet, so that's out.

 

[Tacklewasher]

Re: Repowering

Originally posted by jtexas:<br /> This might help:<br />I/O conversion to outboard topic with pictures<br /><br />what are you going to do with the extra room you've created in your boat?

Bench seat across the back with rod storage underneath.<br /><br />Next question is should I keep the big gas tank (about 30 gals) under the bow? I'm concerned that by reducing the weight at the back, I could end up front heavy. Plus, I would like to build storage up there for jackets, tubes ski's etc. to keep it in the boat should the fishing slow down.

 

[Tacklewasher]

Re: Repowering

Progress so far

 

[roscoe]

Re: Repowering

Hi Tacklewasher, looks like a great project you have going there.<br />Thanks for the update, keep em coming.<br /><br />Make it strong, make it safe, be happy in your work.<br /><br />I would keep the 30 gallon tank. You don't have to keep it full.

 

[Tacklewasher]

Re: Repowering

Can you see the pictures? I was told they could not be viewed by someone else.<br /><br />And as to the tank, I am leaning towards removing it. Last issue is that I can't lift the tounge of the boat right now. It was always hard with the motor in, but with it out it's not possible. May be better once I hang the outboard off the back end.

 

[kdmiller8251]

Re: Repowering

nope cant see pictures

 

[roscoe]

Re: Repowering

The "progress so far" link works fine for me.<br /><br />Wait till you get her all finished, then you may have to reposition on the trailer, or move the axel forward to rebalance it.

 

[Tacklewasher]

Re: Repowering

Haven't added to the page yet, but the motor is out thanks to cutting of the steering cable (I could not pull the pulleys out through where they are located) and I'm starting to clean up the inside.<br /><br />I have to do major cutting to build the splash well and here is my current thought.<br /><br />The transom is 1 5/8 plywood is near perfect shape. I have to cut part of it out so I'm thinking of taking what I cut out to fill the hole. Seal it in with marine tex or something similar and then strap a piece of 1 inch plywood across the full transom on the inside. Since the existing plywood is in such good shape, I'm loathe to pull it out. Once I cut the well out, I can sandwich a piece of aluminum between the plywood and the existing aluminum across the hole, seal it and screw it in place.<br /><br />So I'd have the hole filled (from the outside in) with thin aluminum, the 1 5/8 plywood scavened, a strap of plywood the width of the boat and the height of the transom, then vertical aluminum channel tied into the bottom of the boat and bolted through from the motor mounts. I'm also thinking or using some aluminum angle iron across the width of the boat at the top of the transom.