Transom Modification

[Zenbio]

Hey Guys I been searching the boards for the last 3 hrs looking for advice, or to see if anyone had reinforced their transom. I have a 79' 25 Mac Venture that has a 6hp 2 stroke Johnson outboard. I have spent way to much money on this old outboard. I have rebuilt the carb, the fuel pump, new throttle cable, and had a used out-drive put on it. In all I have spent more then $700.00 on it. Well last weekend when my girlfriend and I was motoring in and I think something broke in the lower gear box/out-drive, because out of no where the engine rpm speed up out of control and the prop stopped turning. At first I thought we spun the prop but it was still on there. It seems to still shift in forward and rev. but the prop doesn't spin. Maybe a shear pin? I don't know but anyways I am getting off topic.

After all that I have went through, I am about done with this motor. So what I would like to do is get a nice 8-9hp 4 stroke 20 or 25in with alternator. I know that I will need a 4 stroke motor mount and that I will have to reinforce the transom. I was thinking about maybe fiber-glassing 1/2 in plywood over the entire inside of the transom. I want to make sure there isn't any flexing with the added weight of about 100 lbs. Looking at a Garelick 4-Stroke Motor Bracket. I really would like to be able to trailer with the motor on. I know the warranty doesn't cover this, but I really don't want to lift a 100llb motor every time I trailer.

So Any Ideas about the reinforcement, motor mount or motor? I have been looking at the Tohatsu and Mercury 8hp 9.8 hp outboards. Any good places to get one? I live in Orlando FL. Do I have to get an electric start in order to get an alternator on it? Transom Modification?

Thanks in advance for your help.

Zach

[JoeVacs]

Hey Zach,
The plywood idea sounds logical to me. I believe that's what I would do. I would bolt it on with carraige bolts and glass it in with epoxy. The bolts would pull it in snug, because of the curve, and the epoxy would seal it and make it rigid. With carriage bolts from the outside you could epoxy over the heads and then paint them and they couldn't leak or be noticable.
I don't know if that's the best way, but it's what I would do.
edit
Actually on second thought, I would make a full transom cover out of marine plywood on the outside, and use carriage bolts and epoxy. On the outside you can cover the whole transom and have more strength, and if you epoxy the edges and corners, and paint it, it won't be noticable.the inside of the transom is probably not smooth, so it would be hard to get a single piece across it. I would reinforce the inside where the motor mount is with another piece of plywood and sandwich the original transom between the plywood on the outside with bolts and epoxy. That would be hard to break or shake

[Bob McLellan]

If you do use the plywood, and it sounds like a good idea, be sure to drill out where any bolts (carriage or otherwise) go through the ply with about a one-inch holes. Fill the holes with fiberglass and resin, then redrill to the correct bolt size. That way, water will not wick into the plywood and rot it out - ruining your reinforcing efforts. This will give you through holes totally in a solid glass areas.

[Zenbio]

Any Advice on where I can pick up a outboard. I am leaning towards the Tohatsu or Mercury 9.8 with electric start, not because I need the electric start but because I want the generator to recharge my battery's.Any advice on a 20in shaft or 25 in extra long shaft?

Anyone ever deal with the online outboard places such as internetoutboards.com, onlineoutboards.com or outboardsales.com? They seem to be the cheapest with shipping and all, but haven't see much about customer service.

I was hoping to find a place that could help me finance the motor. Its kinda hard for me to drop $2000.00 right now.

[smoyer]

I just put a bigger motor and boarding ladder on the transom of my V21 and I did something very similar to what you're proposing, but one of my criteria was to not put any holes through the hull near or below the water line. Inside the laz, I sanded the bottom of the boat from the transom to about 4 inches forward, then fiberglassed in some stringer that were 3/4ths of an inch from the transom. Then I cut a piece of 3/4 inch pressure treated plywood for the left and right half of the transom. There's more curve there than you'd think and you might find it hard to bend a full size piece unless it was thinner. My plywood pieces went to just below the deck-hull seam and it's plenty strong ... my goal with the stringers was to transfer a lot of the torsional force from the cantilevered motor and ladder into the hull bottom which is very strong going forward (the stringers that hold the quarterberths are also for hull strength.

In short, it works great ... the motor is about 100 pounds and there is no flex ... my son and I standing on the ladder is 350 pounds and the only give I can see is in the 1/4 inch stainless arms that the ladder is mounted with. And the ladder was successfully put through sea trials when we found our own private beach on Pamlico sound. I'll add some pictures that might help if you're interested in seeing them (I was going to put this in the mods section eventually).

[dvideohd]

I upgraded - it is the end of the model year... there are discounts...

25" shaft - electric start/charger.

it's going to cost you $1980 - or upwards... perhaps you can always get a better deal...
http://www.onlineoutboards.com/?gclid=C ... 2godcTNumw

Financing? you could get "lucky"..........

Credit cards are moving up their rates...

good luck....

**** I just looked... 2010 prices are going up A LOT>.. really... good luck... ****

---jerry

[Zenbio]

smoyer,

I like your idea. I haven't tried at all to fit any plywood in the transom but did figure it has a nice curve that would be hard to match. I don't really like the idea of putting too many holes in my boat and would like to make it so you cant tell I did any thing from the outside. Pictures would be great. Did you fiberglass it all in? Did you use West System or is there a cheaper resin that works good enough? What kinda motor mount did you use? Can you trailer with the motor on the back? I will fill the wholes with resin so water wont get in. That's a good idea. Did you have any problems with the rudder mounts or did you just extend the bolts?

Thanks for all the help guys.

Yea I am seeing around $2000.00 for anything around 9hp with 20in electric start. I would be fine with even a 07 or 08 that was treated well. I been looking on Craig s list and ebay but no luck. I probably would feel better if I bought locally.

[johnnyonspot]

Just get yourself a used 2-stroke 15hp and a solar panel. Skip the heavy mods, go sailing.

[Pete]

I have a brand new Nissan 9.8 with electric start and extra long shaft on the back of my V22 and hate it. Its a great motor but way to heavy. I have made three attempts at reinforcing my motor mount. I think I finally got it. But I still will remove it to trailer. In hind sight I wish I had saved my money and got a used 2 stroke.

Pete

[DaveB]

I bought a new 9.8 Tohatsu elect. start 20 inch shaft in 2008 and used it once for 5 hrs. and after a 8 Mo. advertiseing on Crag's list and local papers for $1400 I finally sold it a mo. ago for $1200. I took a beating but there are good deals out there, just keep your eye's open.
Dave

Any Advice on where I can pick up a outboard. I am leaning towards the Tohatsu or Mercury 9.8 with electric start, not because I need the electric start but because I want the generator to recharge my battery's.Any advice on a 20in shaft or 25 in extra long shaft?

Anyone ever deal with the online outboard places such as internetoutboards.com, onlineoutboards.com or outboardsales.com? They seem to be the cheapest with shipping and all, but haven't see much about customer service.

I was hoping to find a place that could help me finance the motor. Its kinda hard for me to drop $2000.00 right now.

[Pete]

Also if you think your going to charge a dead battery with one of these motors, forget it. Check out the amp output. They will run your lights if your battery is dead which is nice, but would take two days to charge a dead battery

[Kenny25]

Howdy All, What is a 4 stroke motor mount and how would I know if I already have one on my 83 Mac.25?

Kenny

[Pete]

Looks like motor brackets are listed by HP and wight limit. Some have different rating for 2 stroke and 4 stroke. I saw one that was listed for 20hp 2 stroke or 5 hp 4 stroke. Thats a big difference. I have a 9.8 4-stroke and had to make several modifications to make the bracket stronger then a wet noodle.

Pete

[Rick Westlake]

Also if you think your going to charge a dead battery with one of these motors, forget it. Check out the amp output. They will run your lights if your battery is dead which is nice, but would take two days to charge a dead battery

8 amps - Beija-Flor had a Tohatsu 9.8, and it kept her battery up quite nicely.

But honestly, I didn't give her battery a chance to charge down.

[Sumner]

............I am leaning towards the Tohatsu or Mercury 9.8 with electric start, not because I need the electric start but because I want the generator to recharge my battery's........a place that could help me finance the motor. Its kinda hard for me to drop $2000.00 right now.

If you want to charge your batteries the alternator on the outboard may or may not due the trick depending on your needs. Most of these outboards put out about 6 amps. In my case I use a CPAP machine at night for sleep apnea and it uses 6 amps, so if I used it for 6 hours of the night, which is about normal then I would need to run the outboard for 6 hours to replenish the battery back to where it was the day before and this doesn't count the other things that runs the battery down, such as the depth finder, radio/tape deck for music or the LED anchor light at night (we pretty much use LED lights for cabin light at night).

Now chances are you don't use the electricity we do, but still figure your needs and see how long you would need to run the outboard to recharge the batteries. If you are only going out for 2-3 days and just need to partially recharge then you are probably good to go.

I made ............



http://purplesagetradingpost.com/sumner ... de-13.html

............a generator using a car alternator and with it the two batteries can be charged in 30 to 45 minutes. This is important to us as we are out for extended periods where the batteries can't be charged back at home like they could if we were out for 2-3 days.

We recently also added a 40 watt solar panel and on a recent 3 day trip it kept the batteries up enough that we didn't have to use the generator, but I'll bet they were lower at the end of the trip than when we left. We hope it cuts down on the generator usage, but still need the generator to keep the batteries up on our long trips. I don't have the installation of the solar panel on our site soon, but will eventually.

c ya,

Sum

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