I am fixing up my cousins 14 foot row/ motor boat. With some minor repairs I should have 500 in the boat and trailer. It’s a pretty old boat so I don’t really want to put that much into it. I would like to have an outboard for it.

What motor can I buy pretty reasonably on the new or used market that will give me good service?

Well the purchase price isnt the only thing you need consider.
Best to buy one at a higher price that has been well maintained and serviced very recently with receipts to verify that.
Otherwise you could well spend more on the service to get it up to speed than the cost of the motor.

Wish not to start a products war here but if I were in your shoes I'd look for a Johnson, maybe a 9.9 HP. Most of these were completely dependable. I sold a 1957 model a few years back. Dad fished with it for many years & I after him. I put it through the shop once for a water pump & asked them to give it a check for whatever is needed. It needed nothing. Even the compression was well within the correct limits after all those years. I'm sure there are other motors to consider but that is my findings & in fact I run a Johnson these days, a 25 HP made the last year of the 2 stroke.

I was a Yamaha runner for a long time and bought a new 50 hp. Tahatsu over 10 years ago. It is the the low pressure injected 2 stroke. it has been just as reliable as those old carbed 2 stroke yama dogs.

What kind of speed are you looking ? what is the HP rating?

Boat only has a 10 horsepower rating. I am in the process of replacing the wood on the transom. What kind of sealer should I put over the wood?

I would second the 9.9hp Johnson or Evinrude, they are tough motors and parts are everywhere and you can get a Clymer manual that covers all the repairs. I'm running a pair of 15's, same motor different carb. that are almost 50 yrs old and they are just plane reliable. I use the electric start one for fishing as your always starting and moving from place to place or up wind for a new drift, this year I put a new water pump in, rebuilt the carb and a new fuel pump, everything came from Amazon for less than $1oo including the repair manual. The manual start 15hp I use during duck season as I pull the trolling motor and starting batteries from the cargo hold and have more room for decoys. Running a new synthetic oil (Opti II) has just about eliminated smoke and plug fowling.

As I see it, you should be shopping for a twin cylinder two stroke. The four strokes are heavy and often only a single cylinder in the small hp sizes and they vibrate more than a twin. Any small outboard gets terrific gas mileage so mixing gas and 50 to 1 oil for an older one isn't much of a hassle. My buddy who fixes outboards said to stay away from the low profile 9.5 Evinrude Litewin. Our Canada camp owner ran the 9.9's with good luck if he could keep guys from augering them through the sand and plugging up the water pump. He later went to the 15's that erich mentioned which were better, faster and didn't seem to use any more gas. I switched to a 7.5 and later a 9.8 Merc because I wanted to get away from sheer pins on the smaller OMC engines. Our 40 year old Merc 9.8 is on the pontoon boat and starts first or second pull and has been a great motor. The wife also had a newer 9.8 Merc that shifted with the twist grip, but I liked my older shift on the side 9.8 more so we sold her's. A motor in the ten hp range should plane a 14 footer while a smaller one probably won't.

"Any small outboard gets terrific gas mileage,,,"
I disagree. We did fly in trips to Hudson Bay with a 2 stroke and a 4 stroke small engines. 2 stroke burned almost twice as much fuel as the 4 stroke. 2 stroke was lighter than the 4 stroke. 2 stroke much louder.

What sealer should I use on marine grade plywood. Some have recommended epoxy sealer.

I would recommend sealing the plywood with epoxy. I used some West Marine epoxy on the wood in my jon boat. I thinned the first coat with acetone so it would penetrate better. There are a few boating websites that sell epoxy.

After the epoxy I have to add a sealer?

I used 1 coat of the thinned epoxy followed by 1 coat of the full strength epoxy and then a coat of high quality urethane marine paint. Most boating supply stores like West Marine will have everything you need.

It is NOT West Marine epoxy. It is WEST epoxy (totally different company) that just happens to be sold by West Marine, among many other chandlers.

Also it is extremely foolhardy and counterproductive to add anything (such as acetone) that is not specifically recommended by the formulator. WEST epoxy does not need to be thinned--it is formulated to penetrate wood (Wood Epoxy Saturation Technique). There are no solvents in WEST epoxy. It cures, not by the evaporation of solvents, but by being catalyzed.

Thanks for the correction on the brand.
The acetone flashes off long before the epoxy hardens. The epoxy I was using was the consistency of honey, it definitely would not have penetrated very well.
My method worked for me. YMMV

Tohatsu is the oldest outboard manufacturer in Japan.

I have a 9.9 Honda Four Stroke.It will get me about 20 miles on a gallon of gas.On my 12ft boat it will push it along at 23mph.It's a little heavy,but plenty of power.

This is absolute,truth
The only thing you may add would be thier fillers to get the consistency you desire

Epoxy has no VOCs
And that's the way it was designed
Great stuff made in Bay City MI
They have fantastic tech services if you need help with your project

Hank


https://www.westsystem.com/

The 9.9 and 15 Mercs
With shift in the handle are really great motors IMO
But there are many good motors
With BRP getting out of the market getting parts maybe more of an issue than it has be for J/E
We have been spoiled and been able to get parts for old old motors

I hope that will not change
Hank

Would I be doing badly to buy an older 2 stroke 9.9, or should I pony up the cash for 4 stroke?

In April of 2019 i bought a new left over 2018 20 hp 4 stroke Mercury short shaft with electric start for $2.400.
I had been looking for a nice used engine for months and found they werent all that much less.

Any bad thing about the four stroke, is the weight.

wow heck of a deal