Deep V aluminum boat - what HP outboard motor?

[Walleye-Seeker]

I have a 2001 Lowe Sea Nymph WT1677 Deep V 16' lg. aluminum hull. The 9.9 Johnson 2-stroke engine that came with it will suit a number of my local lakes 10HP limit, but just doesn't cut it at the larger reservoirs. I like the wide beam and stable deep v hull on the rough water, but the big drawback is speed. I waste an hour getting back & forth from the boat ramp, so fishing after work for 2-3 hours isn't as much fun as it sounds. I have only been able to get 8.0mph with one adult passenger and a slight tail wind (per my Garmin Colorado.) I desperately am looking for an outboard between 25hp and 50hp (I believe the hull is rated 50 or 55 max.) Question is this, What HP would it take to reasonably achieve getting on plane quickly and reliably, and what would be overkill? I would like to get 25-30mph at WOT if possible. One more thing, my boat is a tiller controlled model, so moving weight forward is not going to help much with my fat behind at the helm I'm considering a mid-80's model Johnson 35hp that my local mechanic is working on. There are several motors in my area from 20-50hp that may be available. USED motors are a must, newer 4-stroke motors are too much $$$ and therefore, ruled out. Thanks for any help.

 

[CATransplant]

Re: Deep V aluminum boat - what HP outboard motor?

I believe that the 35 will do the job for you. It's a lot lighter than the 50, and less of a handful with the tiller.

However, do move batteries and fuel tanks forward. It will help compensate for the additional weight and will help you get on plane easier. Same with livewells.

That tinny would fly with the 50 on it, if it's rated for that, but you'll still move right out with the 35.

 

[Walleye-Seeker]

Re: Deep V aluminum boat - what HP outboard motor?

If the deal doesn't work out, or the motor is not repairable, would a 20 or 25 work O.K.?

 

[Walleye-Seeker]

Re: Deep V aluminum boat - what HP outboard motor?

Will there be any problems with weight if I leave the 9.9 on a kicker mount next to the new motor? I need to keep it on so I can go between my local lakes without too much trouble.

On a side note, I live in an area that gets considerable Ice / snow and sub-freezing temps in the winter. I currently wrestle my 9.9 down the stairs to my basement every winter to keep anything from freezing. I've been told that this is not necessary if the motor is lowered to a normal 'operating' position where cooling water can drain out the openings. Thoughts?

 

[CATransplant]

Re: Deep V aluminum boat - what HP outboard motor?

Yes, you can keep the 9.9 on the transom, along with the larger motor. However, you'll want to make sure you can tilt it up so that the leg is completely out of the water when you're not using it. Otherwise, it's a serious drag on your boat when you're using the larger outboard, and will probably blow water into the boat. Even my fish finder transducer almost gets water into the boat when I'm underway.

As for taking it off the boat in the winter, you don't have to. As long as you lower it to operating position, all the water will drain out of it. That said, you also have to check your lower unit oil to make sure no water has intruded into it. That water can freeze and crack the lower unit. Same thing with the big motor.

What I do is to drain and refill my lower unit every fall when I put the boat away. I just have a 6hp, so I take it down to the basement for the winter, and do any work I plan to do on it during the cold months.

Your Lund's transom is plenty wide for both motors. Center the larger one, then position the 9.9 just far enough to one side so it won't interfere with the large motor's steering travel. Which side? The side you sit on. Otherwise, you'll have to change positions to steer with the 9.9.

Finally, check your local lake regs and make sure they don't care if you have a larger motor mounted, as long as you don't use it. Most are OK with that, but it's a good idea to detach the fuel line from its tank on lakes with an under 10 hp limit. That way, the lake patrol can see that you don't intend to use the larger motor.

When I take my little boat to a no gasoline outboard lake, I leave the fuel tank at home. That way, the lake patrol can see that I have no way to use the gasoline outboard.

 

[jdsgrog]

Re: Deep V aluminum boat - what HP outboard motor?

If you put numbers in the crouch formula, it would seem that the 35 can get you up to about 24-26mph with a 35hp at 1300 lbs (about 750lbs more than the boat's dry weight). Personally, a 35hp is about as low as I would go. I have a 14ft lund, with a '67 33hp on it. With about 1000lbs total weight (boat motor, trolling motor, batteries, gear, fuel and tanks, myself, etc.), I get about 27mph. If you go with a 25hp, I'm assuming you would get in the low 20's.

Also, remember that hp ratings are different than in the past. now it is rated at the prop shaft. in the past (before some time in the 80's), it was rated at the powerhead. So an old 35hp motor is actually 10-15% less. My 33hp is probably about 28-29hp at the prop shaft.

 

[Walleye-Seeker]

Re: Deep V aluminum boat - what HP outboard motor?

Thanks for all the info! This is my second post, and I must say that everyone is very helpful.

After reading your response CA, I am sure I'm on the right track for what I need. Also I'll have to look up the formula to see if I can run my own numbers for additional questions or motors that I run across (at least I'll know what to 'expect' from each motor in a best case scenario.

On another note, I just changed my plugs in the 9.9, the electrodes were eroded and a little rusty (I just bought the boat this year- they must be the originals!) Hopefully I can get to 9mph now, until I settle on a bigger powerplant!


So much water, so little time!

 

[5150abf]

Re: Deep V aluminum boat - what HP outboard motor?

I have a 16' Sea Nymph with a 50 and the best it has ever done was 30, normally between 27-29 depending on the current, mine is a bass style boat, 2 casting decks,2 livewells and everything but the kitchen sink so it is a little heavy but still runs really nice.

I ended up mounting my battery in the point of the bow to help with weight distribution, I hate walking up hill all night.

 

[stjernefodt]

Re: Deep V aluminum boat - what HP outboard motor?

I have the same boat as Walleye-Seeker, mine is a 2004 Lowe 1677WT.
It came with a 2005 25 HP 2-stroke Johnson w/electric start.

With 2 people, fishing gear, 2 batteries, trolling motor, 8 gallons of gas, (total 1300 lbs) it goes up to 21 mph WOT, or 25 mph with just one person.

I love this boat, and I'm recently maxing it out to a 50 HP 4-stroke Yamaha, because I usually fish with 4 guys and I need the extra power. My current motor is up for grabs, you can see it running here on my Lowe:

http://www.youtube.com/watch?v=aVofu4R4xs4

I'm also searching for a kicker, and I think I'll settle on a 6 HP Suzuki 4S (weighs 55 lbs). I've seen it mounted on a similar boat and it should do the trick for trolling and and for emergencies. The transom rating for this boat is 346 lbs.

Some pics of my boat.

 

[Philip_G]

Re: Deep V aluminum boat - what HP outboard motor?

nice boat!

 

[CATransplant]

Re: Deep V aluminum boat - what HP outboard motor?

A lean, clean, fishing machine is what you've got there. Nice!

 

[ezmobee]

Re: Deep V aluminum boat - what HP outboard motor?

I agree. That's a heck of a nice rig.

 

[Philip_G]

Re: Deep V aluminum boat - what HP outboard motor?

that thing is absolutely perfect, I can't think of anything I'd even change.