Need recommendations for an electric motor (thrust power)

[mpmurray]

I just bought my first Venture 17. I'd like to get a motor, mostly for safety. I'm leaning towards electric motor.

I read that a boat should have 5lbs thrust for every 350lbs of vessel weight. I believe the V17 is about 900lbs. translating to 12.8lbs thrust. Most electric trolling motors I see are above 40lb thrust!

Any recommendations on power , length of motor shaft, etc. will be greatly appreciated!

michael

[Bawgy]

I bought the 37 lb thrust minn kota on sale at Walmart for my Venture 24. I would say it moved it around in the lake ok for getting out of the cove. I would not expect it to get you out of trouble in winds over 15 mph though (on my V24 2100 lbs). I am trying to remember my speeds were about 2-4 knots most of the time.

I would recommend a small engine instead if safety is your main concern A small 3.5 -5 hp will do a much better job

[Catigale]

A British Seagull, 200 USD off ebay, complete with a spinning flywheel of death, would complement that Venture perfectly.

[Moe]

If you know the trolling motor's current use in amperes, multiply that by 12 volts and you come up with watts, i.e. 50 x 12 = 600 for a 50 amp trolling motor. There are 746 watts per horsepower, so 600/746 = 0.8 HP INPUT. Since motors aren't 100% efficient, you won't see that at the prop shaft, where gasoline outboards are rated. Not much... maybe 1/3 of a 2 HP Honda. Think about that when you're thinking about pushing the boat through wind or a head sea.

A 45 pound Group 24 deep-cycle battery is rated somewhere around 75-80 amp-hours, so you'd think that should give a 50 amp trolling motor about 1-1/2 hours use, right? Nope. That amp-hour rating is given at the discharge rate that will take it from full charge to fully discharged in 20 hours. The spec that's a little closer is the Reserve Capacity rating, or the time from full charge to fully discharged at a discharge rate of 25 amps. On a Group 24, that's around 120 minutes, or about 50 amp-hours. Because of the same effect, a 50 amp discharge will only give about 50 minutes from full charge to full discharge.

But there's more... You don't want to discharge your deep-cycle battery below about 50% charge if you don't want to be replacing it 2-3 times as often. So now you're down to about 25 minutes use, about 12.5 minutes from slip to out of the harbor and back. Coincidentally that's about what a 2 HP Honda would give you at full throttle on its one-liter fuel tank. Difference is, you're carrying back and forth from home at most a two-pound, one-liter MSR fuel bottle to refill each weekend, instead of lugging a 45 pound battery home if your slip doesn't have electricity. You certainly don't want to leave a partially discharged battery sitting in the boat because it will sulfate and have a shorter life.

The 2 HP four-stroke Honda would put about 30 pounds on your transom, about what 4 HP two-strokes weighed when your Venture was designed. A trolling motor and Group 24 battery could go twice that.

That's why many who've tried the trolling motor route wind up with a gas motor anyway. Like others here, I don't think it's a good idea, at least unless you have an onboard charger and power at your slip.

--
Moe

[Divecoz]

Hey Mike did ya get all that?
But Moe is right! BTW Boaters World has a Tohatsu 3.5 hp - 4stk? for $895.00 Lots of reasonable priced small used outboards around right now as the season is over. No doubt Moe was confident that your now aware that a trolling motor just wont hack it or he could have really burst your bubble with how long it takes a Gp. 24 to fully recharge with a small say 10 amp charger.

[mpmurray]

Hmmm....sounds like folks are advising for gas motor. I'm open to this also.

My Venture17 cost me $950. I'm having a hard time with the notion of paying almost as much just for a motor! Maybe I'm cheap, but that's my feeling.

If I go for gas motor, any suggestions? I'm thinking 2-4hp, with integrated gas tank. Any brands/options to look for/avoid? 2strk vs. 4strk?

(maybe there's another discussion on this for a V17 that I didn't find)

Thanks, michael

[Divecoz]

Mike:
Toys can be expensive but it sounds like yours wont be all that bad. You can honestly pick up a used small motor for a couple hundred dollars.
4 hp w/built in tank etc. 2 or 4 str. ? 2's are cheaper and lighter. Your not going to be motor sailing so IMHO get a 3 to 5 hp. 2 str.

[hart]

For what it's worth, I have an old 2 stroke Johnson 5 HP on my 222 and it does just fine. Agreed, you aren't going to be motoring much so 3 to 5 horsies will be dandy. Search your classifieds, the little classified papers they keep at the gas stations for 50 cents, and craigslist if you have it. Be patient and you'll find a good deal.

[Moe]

It's at the opposite end of the environmental spectrum from an electric motor, but our 4 HP two-smoke pushes our heavier Capri 18 with power to spare. Problem is, it's a 15-inch "short" shaft and the boat really needs a 20-inch "long" shaft. I don't know for sure, but suspect the V-17 does also.

Aside from leaving an oil slick in the water and smoking out all the mosquitoes at start up, and having 360º degree steering instead of reverse, it has a couple of advantages. One is that it only weighs about 27 pounds. The other is that a two-stroke is smoother running than a four-stroke and ours is a twin cylinder, so it's even more smooth than a single-cylinder four-stroke.

There's also a lot less to go wrong. Plan on replacing the water pump impeller on an older motor though... few owners ever do. If you can, do a compression check on it, but at least run it with the foot in a tub of water to see if it will idle and run at low speeds smoothly. You can check the water stream from the motor to see if it's weak.

The forums at iboats.com are a great source for getting help and finding parts for older motors.

Hope this helps,
--
Moe

[Catigale]

Environmentally you can absolve the 2 stroke sin of putting some oil and fuel into the environment by buying a used motor (whatever kind you care for) and saving the planet the impact of building a new one.

[R Rae]

Dittos to you Catigale. I believe recycling older stuff is the way to go.


However............As most of my rolling stock dates back to the eighties. Couldn't I save up and at some point acquire just a wee Mini Cooper 'S'

[Divecoz]

Dittos to you Catigale. I believe recycling older stuff is the way to go.


However............As most of my rolling stock dates back to the eighties. Couldn't I save up and at some point acquire just a wee Mini Cooper 'S'

The Morris Mini's are still available as we saw rolling down the highways and the byways here outside Chicago last weekend. Must have been a show of sorts somewhere because they were everywhere!
My 11 Y.O. grandson while pointing out the size of the wheels on those things, said Papa lets put a body on the Go-cart it looks like they did hahahahaha
BTW we saw left and right steering

[Bawgy]

Ill Stick with my Morris Midget Thank You

[Moe]

...he could have really burst your bubble with how long it takes a Gp. 24 to fully recharge with a small say 10 amp charger.

That's an especially good point to make for those considering trying to recharge a house battery with a small solar panel.

We bring our previous owner's Group 24 West Marine house battery home each weekend since our dock doesn't have power (or water). I like to slow charge it with a Battery Tender Waterproof 800 we usually keep on the motorcycle. Putting it in perspective, that's about the same as a 12 watt solar panel that gets its rating at 15 volts at 800mA.

It takes anywhere from 48 to 72 hours to recharge at that rate, depending on how much we've used the previous weekend (staying above 50%). Considering we'd get 6-8 hours of effective sunlight per day, a 12 watt solar panel could take as long as 9-12 sunny days to recharge our house battery after a 2-3 day weekend's use.

We do have an on-board three-stage 10 amp charger, mainly for charging in the driveway, but also if we ever take a longer trip and stay at marinas with dock power. Close to 50% charge, the Group 24 only draws something like 7-8 amps from it, and that's in the 14.4 volt bulk mode. That gives us 2-3 amps for lights, music, etc. By 80% charge, where the battery's acceptance rate is low and getting lower, it's drawing less than 2 amps. The rule of thumb is that it takes as long to charge from 80-100% as it does from 20% to 80%! I haven't checked it, but I'd guess it would take 8-10 hours from 50% with the 3-stage 10 amp charger.

Also, don't let a 3-6 HP outboard having an alternator influence your motor-buying decision. At this horsepower level, even if it does have an alternator, the output is barely enough to run navigation lights for night use (intended purpose). And you won't be motoring anywhere near enough to recover from even one night of anchor light use (6-8 amp-hours), much less music or radio use.

--
Moe

[Divecoz]

Thanks Moe, I didn't have the figures but knew you would or could post them.
Starting to get a little chilly up here isn't it...
Boat is in the drive next to the garage. Building cabinets and such this winter. Never did get to building the custom coolers and as we have no need for them as it turns out, glad I didn't waste the space.
One thing that seems not to get posted as much as it used to is . . . . .
Waiting awhile and using your Mac before you start adding Mod's and Buying Stuff. I still have somewhere in the garage a wind indicator for my rotating masted M