Outboard motor for my drift boat

I need some help here. I just bought a pristine 1964 Merc 9.8 for my drift boat. It is supposed to be a long shaft but when I got it home and mounted it on the transom it looks too short. It measurers 20" from top of transom to cavitation plate but the cavitation plate is even with the bottom of the transom. It looks like the prop will barely be in the water. Of course this is mounted on the trailer so I'm eyeballing it. The boat is in the process of restoring and I could notch the transom to lower the motor. It has a metal plate that mounts over the transom to accommodate the motor. any ideas?

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Permalink Reply by Rick Newman on July 26, 2013 at 12:27pm

Mark, can you provide a wider angle picture of your boat. There were boats built for the Rogue that were purpose built to do just what you are describing. They have a different profile than a McKenzie boat. Check it out in Roger Fletcher's book. There is one in Coeur d'Alene and I could see how the stern was lower than the bow. It also appears that your boat might alreadyhavea cut out, have you removed the metal to see what is going on underneath it?

I'm glad to see that a variety of opinions and thoughts are being presented. Lots more info to be shared this way.

Rick N

Permalink Reply by Mark Heskett on July 26, 2013 at 3:14pm
Permalink Reply by lhedrick on July 26, 2013 at 3:03pm

I too think that motor is too much.

At most I would run a light 5 HP.  A rocked hull is just not the thing for anything  but slow speed.

The lines look okay to me.  It's not going to plane but rather the stern is going to sink and with the operator back there for a little push on slow water I think you will do fine.  As for full speed, post a report.

Permalink Reply by Mark Heskett on July 26, 2013 at 3:18pm

Not planning to go fast, mostly pushing back upriver and maybe some lake fishing nothing too fast.  Thanks for the input.

Permalink Reply by AJ DeRosa on July 26, 2013 at 10:08pm

This is a good discussion.  I've fussed with motors on these funny river boats for awhile and they can work just fine with a little bit of understanding of the limitations of the hull when propelled backwards.  Understand that the transom end on a traditional Mc Kenzie River Boat is actually the bow.  See Roger's book for a complete understanding of this if you don't already know.  Keith Steele was famous for telling the story to us rookies and I was fortunate enough to get my lecture in 1988. 

 

Since you are pushing this boat backwards consider it as a displacement hull,  it will work fine at slow speed.  It will get squireley at higher speed and don't expect it to plane.  It works fine with a lightweight electric motor cuz it doesn't have enough power to push too hard.

 

The old boats that will plane with power on the transom are the Rapid Robert, which I can speak for as I have been running one that way for many years,  and probably Pritchet's Rogue River Special.  I have no experience with the Rogue River boat but it seems to have evolved with power from the transom end for that purpose.  Would love to learn more about that Rogue boat.

 

Having said that, I would still put that old Merc on the boat and try it out.  They come from the same era and look great together. 

Just throw it on there and take it for a ride in a pond.

 

AJ

Permalink Reply by Mark Heskett on July 27, 2013 at 9:36am

Man this is great the amount of feed back and ideas I'm getting. Now I'm having an conundrum whether to put a 2 inch cut out in the transom or finish the restoration and put the motor on as is a try it out on the local lake. Thanks guys.

Mark

Permalink Reply by Chris Patterson on July 29, 2013 at 8:46pm

I would not cut out the transom.  I think you are going to be fine as is. The transom is going to be pushed deeper as you apply power and the bow rises.

I used to hang a 6 hp off the back of my fiberglass guide boat and would have liked having your 9.8.

Your boat is not going to plane and the bow will point to the sky when you give it the gas but you will be able to inch back upstream to refish a good bank.  Pushing downstream when you have miles of river to go and the sun is setting...you are going to love that motor.

Have fun.  It is going to look awesome.

Permalink Reply by Jack Rose on July 31, 2013 at 7:34pm

Mark, that's not only a great looking motor, but it's a great motor, too.  I have essentially the same model, but a few years older.   Mine is a 10 hp 1957 Mercury Mark 10 Trol-Twin, just like this one, but it's all red. 

Some of the old boat motor guys refer to these motors as the Darth Vader series for obvious reasons.  And those guys will be awfully helpful when it comes time to do any maintenance.  There are several sites on the web that are quite helpful.

Speaking of which, if you haven't already, you ought to change out the impeller.  If it's not been used or changed in the last couple of years chances are that it's dry-rotted.  You'd hate to be the guy who toasted a 50 yr. old motor.

I've never put mine on my drift boat (same color as yours, too), but based on having used it on my 12' aluminum john boat, that hp should be perfect for your boat.

As for the tiller extension, you'll have to decide on the length after you get it set up, but I've had good luck using a piece of PVC pipe that slipped over the tiller handle.  I cut two 3" slits, lengthwise, in one end of the pipe to slip it over the handle, then used two worm screw clamps to tighten it down.

Also, you've probably figured this out, but use the trim adjustment pin on the mount to tilt the motor so that the cavitation plate is as parallel to the water line as you can get it.  Obviously, given the rocker of a driftboat, that will change with acceleration, so you'll have to experiment and get an average.

Good luck,

Jack

Permalink Reply by Mark Heskett on July 31, 2013 at 7:51pm

Jack

Thanks for the info. It has a new impeller installed but thanks for the heads up. I want to make this motor work. I'm old school like  of guys here . I fish split cane rods that I build and restore and I think this motor is going to compliment and work on my drift boat. Man I really appreciate the input you guys are giving me.

Mark

Permalink Reply by Bill Craig on July 31, 2013 at 11:03am

I'm fishing the Manistee river in MI below Tippy dam. Not as turbulent as those western rivers but still some pretty good current. Last Fall I was there with my jet sled. I had two heavy duty type anglers in my boat and with that load it would only plow water up river. Then I saw another boat with 3 people (somewhat smaller anglers). It was a wooden drifter. The wood boat was moving effortlessly up river. When we got back to the boat ramp I asked the boat owner about his wood boat. He and his father made it from plans and he gave me the source. I was so impressed I ordered the plans and not have a similar boat almost completed. The wooden boat that was moving up river so easily had a 4 HP outboard motor. It wasn't planing but not plowing water either. This Fall I will have the same configuration but the motor I have is 6 HP.

Permalink Reply by Chris Patterson on July 31, 2013 at 12:20pm

Bill, do you have ant more details?  A website maybe?

Permalink Reply by Bill Craig on July 31, 2013 at 7:35pm

www.dhdriftboats.com It is a Don Hill 16 ft boat.

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