What is the best size motor for a drift boat?

drifter24 · 11-13-2002, 07:23 AM

I have a 17' Willie's drift boat, and I am looking to get a motor for it. I know I want a four-stroke, but I'm not sure about the size. I've seen a lot of 8 and 9.9 hp motors. Will a 17' boat handle anything more than that or is a 9.9 my best bet?

Hogmaster · 11-13-2002, 07:31 AM

Your problem will be slowing down. Also weight on a 4 stroke.

Personally I would go with an 8 or if you get a 9.9 or even a 15 do not do so unless you also want to invest in an electric troller.

When you see the DBs with bigger kickers dragging two huge sea anchors and a 5 gallon bucket still doing warp speed upstream trolling you'll understand what I mean.

You are never going to go real fast in a drift boat with a motor anyway, so consider saving some dough and going for the smaller plant. It will still get you where you need to be within a knot or two at top end, but the trolling issue is very real at the slow end of things.

This isn't worth much. I don't even own a DB. Just an observation of friends and others I have seen with them...

Tilla · 11-13-2002, 07:35 AM

Not sure about the 4 stroke, but more hp won't get you much more performance. I don't think there is more speed to be gained past 6 hp. Go with the max hp rating listed on the boat. Most driftboats have a 8 or 10 hp max rating.

AtWorkALot · 11-13-2002, 07:47 AM

I agree with Tilla. A bigger motor won't necessarily get you "there" faster.

Captn · 11-13-2002, 08:15 AM

I have owned a drift boat for the last 15 or 20 years, and a few different brands. I know that 4 strokes are the rage right now, but for a weight/hp ratio, the two stroke is difficult to beat. I have a 6hp 2 stroke, 8 hp 2 stroke, and a 15 hp 4 stroke. The motor I like the best on my guide model Willies (16/54) is the 6 hp with the dole fin. Nice for trolling and it goes just about as fast as the other motors. It is nice and light, so that I can easily reomove it or put it back on and I don't have to troll with a bucket tied behind me. Good luck. By the way, a friend of mine is selling his Merc 9.9 long shaft 4 stroke. If you are interested, e-mail me.

SouthCoastStu · 11-13-2002, 08:40 AM

I had a 5hp Honda on my 16' Diamond Back for about 7 years. My observations: the one cylinder 4-strokes vibrate a lot :depressed: ; I needed a trolling plate to get me down to the "right" speed; wouldn't go significantly faster with bigger motor. I don't use the motor on the driftboat now, it's found a new home on the back of the sled :smile:

I would go with the 2 cylinder, 8 hp Honda. A Merc 9.9 (do they make an 8?) 2 stroke would also be a real good choice and cost a lot less. I personally don't like the smoke, gas mixing , or the oil slick in the water.

You still might need some way to slow the boat down to troll (sea anchor, trolling plate). Have you seen those combination hydrofoil/trolling plates?

Hope this helps.

A-Boss · 11-13-2002, 08:42 AM

Couple more questions. I was looking at getting a Yamaha 8hp 4-Stroke for my 16x48 Aluminum DB.

According to their web site they have two models. A Portable Version (83lbs, 20in max shaft length) or a High Thrust version (102 lbs 25in max shaft length, power tilt).

I've got a motor well cut out. How long of a shaft would I need? I saw an earlier post about the cut out limiting the turn radius when turning one direction. Would I be better off getting a longer shaft and not using the cut out?

Since its geared higher would the high thrust version allow me to troll slower? Would I lose much top speed with it? How useful is the power tilt feature? Is it worth the extra weight?

Any insight would be appreciated.

RogueFishr · 11-13-2002, 08:46 AM

I have a Willies 16/54 and the following motors: 8hp Honda 4 stroke, 8hp Merc 2 stroke, and a 15hp honda 4 stroke. The 4 strokes are noticeably heavier for sure. Also, they have more torque and you can not slow them down enough. I ordered a special prop for the Honda 8hp and still couldn't slow it down enough. The 2 stroke is the best setup for slowing down. Top speed is not an issue with a drift boat. The 15hp Honda will not do that much faster than either of the 8's. It just has more power and I can get up one specific rapid here locally. If I had to get rid of all but one motor, I would keep the 2 stroke.

RF

RogueFishr · 11-13-2002, 08:58 AM

My Honda 8hp was a 2000 model. After my $100 super-slow low pitch prop (I think low pitch) didn't make much difference in slowing me down, I tried a trolling plate. It STILL wouldn't slow down enough. I had to make a locking pin and bracket to lock the plate down to get it slow enough. As for the power tilt, I don't think I would sacrifice any additional weight for anything.

RF.

cureless · 11-13-2002, 09:04 AM

Great topic

My DB 16X54 has a 8hp Merc. 2 stroke.

You will find as most have said that no matter how much HP you put on a DB that plow will only go so fast.

My additional question is (more impotant than top speed) but trolling speed.

The last few years I have noticed while trolling with the current I could not slow down enough. I would pass up all the other boats who were catching fish, I know this has had a direct impact on my catch ratio fishing from a DB.

HOW DO I SLOW DOWN?? when trolling with the current??

trolling against the current with a bucket/sea anchor worked out fine.

Applegate · 11-13-2002, 09:07 AM

What application are you looking for? If you strictly want to troll then a 6-8hp will do the job just fine. I have a 15 merc on my boat but use it primarily to back troll against the current in the river and, as RogueFishr does, to get up one specific piece of fastwater. What ever you are intending to use it for the most should dictate what you purchase.

TheTexan · 11-13-2002, 09:19 AM

One additional question, What about the electric motors? What thrust would you recommend and what are they good for?

thanks

bllelk · 11-13-2002, 01:00 PM

The prettiest drift boat on the Nehalem has a 8hp 2 stroke Johnson. We have also found that sometimes when trolling with the current we simply go too fast. So up comes the motor and we break out the oars and row. This also allows me to work back and forth across the current to cover a hole better than simply going straight up or straight down in the parade. [img]graemlins/idea.gif[/img]

SouthCoastStu · 11-13-2002, 01:35 PM

When I had my 5hp Honda long shaft on the drift boat, I put a "Happy Troller" trolling plate on it to slow down. With the plate locked all the way down, and full throttle, the boat would hardly move. First, I cut a 3" diameter hole in the plate. This got the "right" speed, but the rpms were pretty high. Next, I cut new notches, so the plate was at a 45 degree angle. Perfect speed (for me), with the throttle just above idle. I don't troll with the DB anymore, so if anyone is interested I'd let it go for $30 (I think it was $60 new).
One draw back to the trolling plate setup was that I have a motorwell in the DB, when I wanted to kick the motor all the way up (coming up to the bank) I would have to drop the trolling plate into the down position so it didn't hit on the transom. With a motorwell, I think a short shaft would be better.
Hope this info is helpful to someone...

wetaline · 11-13-2002, 01:49 PM

Someone had questioned using the Motor Well on their boat. I've got a Alumaweld and tried using it w/ the cut out removed... and found it ran much better w/ the plate in place so that there was no motor well...

when it was removed and pushing forward at full throttle the engine would be practicaly submerged.

However when in place, w/ out any weight in the back of the boat the prop would come up out of the water - just have to remember to keep the weight in the back when running the engine.

graybeard · 11-13-2002, 01:59 PM

I put dual batteries up front, tie-strapped the cable along the gunwale back to the electric motor. Drift boats don't have much drag in the water, electric motors work great.

Drachir · 11-13-2002, 03:24 PM

I had an 8 hp Merc 2 stroke on my DB. It worked just fine, and the shift in the handle, is great when using the extension handle.

It will do no good to get any more then an 8 hp. The hull design of a DB does not lend itself to going fast. The most important thing is weight, and the 2-stroke is the choice for that. I can't imagine trying to row through rapids and have a heavy 4 stroke kicker on the back, that does not sound like any fun!! Good Luck!!

Captn · 11-13-2002, 03:32 PM

When I replied above, I did not mention that the 6 hp was a little Yamaha, it is a two cylinder, and they are very smooth. I have also used my 38lb thrust electric motor, it is nice to pull out when doing a long drift, but for trolling, the 6 hp is overall the best bet.
The other choice was a Merc 8 hp, and I did get a reduced thrust prop that worked really well in the bay for trolling, it must have worked pretty well as I used it in the Tillamook bay for over 12 years. But now I have the little Yamaha and like it even better, but you need to have the dole fin. I have not seen the trolling plate/dole fin combos--sounds interesting. Hope this helps some--
By the way -- the rivers are in prime shape for tomorrow!!!!!!!!!