How big should my kicker be?

[formulafisher]

I have a 23ft formula that weights about 4500lbs im looking to put an kicked motor on the boat something that will bring me i if my engine fails. How big of a motor should i go with

 

[crazy charlie]

Re: How big should my kicker be?

I was going to suggest something at least 10-15 hp ,but it really depends how far you may need to go and what type of conditions.For a smaller lake you can do fine with 10-15 but in the ocean where you may have to get through an inlet ,i would up it to 20-25.Charlie

 

[phatmanmike]

Re: How big should my kicker be?

ive always heard the rule or 10%<br /><br />if you have a 200 main, get a 20 kicker.

 

[Luna Sea]

Re: How big should my kicker be?

I'd think a 15 would do for most situations. There's plenty of towing ins. companies too......

 

[Elmer Fudge]

Re: How big should my kicker be?

I say get the biggest that you can afford

 

[umblecumbuz]

Re: How big should my kicker be?

Don't know where you fish, but don't forget current or tide.<br /><br />A big motor will almost ignore 5kts against you, but a tiddler on a wide-beamed heavy boat might only make 5kts max in still water.

 

[walleyehed]

Re: How big should my kicker be?

5HP per 1000lbs. of boat.

 

[Boatist]

Re: How big should my kicker be?

I have a 15 HP long shaft kicker on my 21 foot 2800lb boat and it is not big enough. Sure on a inland lake with no sea or wind mine will do almost 5 MPH wide open. That fine to get me in. <br /><br />Out to sea with 7 foot swells and a 25 knot wind with gust to 37 I can hardly keep the bow into the wind and swells. If I half to quarter between swells to matain my heading and keep a safe angle on the swells most of the time it does not make the turn fast enough. I never had to use it to come in but have praticed with it to see what it would do. I hope to get a 20 horse Honda as only motor light enough to mount on my type motor bracket.<br /><br />If I were you and your looking for something to get you in in a rough ocean i would go at least 35 HP.

 

[tmcalavy]

Re: How big should my kicker be?

The ladies will tell you, the bigger the Johnson the better.

 

[MIKENVAHBEACH]

Re: How big should my kicker be?

I have a Honda Bf15 kicker on my 22' Pursuit, it weighs around 5000lbs. The kicker will push max 7 knots in still water, make sure you have it propped correctly. A 15hp should work fine.

 

[walleyehed]

Re: How big should my kicker be?

Once again....rule of thumb when considering kicker for (In this case) pro Walleye applications from small lakes to the great lakes, is 5HP per 1000lbs of boat.<br />5000lbs with a 15 is a bit shy for anything other than calm condition, as I think Boatist explained in his experience, which has also been very simular to my experience in size/weight.

 

[Capn Mike]

Re: How big should my kicker be?

Since a kicker isn't intended to put a boat on plane, a 9.9-hp motor will push your boat as fast as a 30 (the displacement speed formula comes into play here). I had a 15 hp. 2S (orginally on a light aluminum boat) as my first kicker on my 23' Seaswirl (also 4500 lbs.) I traded it for a 9.9 4S with high-thrust gearing and it's been much more satisfactory. Pushes my boat just fine through 5-8 mph currents on the Columbia River.<br /><br />However, what it can't handle are gusty or high head winds. In that case, I have to turn on the main engine....and even then, a 50-hp kicker wouldn't work. It just flat takes a bunch of horsepower to keep a typical power boat headed into a headwind, and no kicker will work satisfactorily. IMO, more than 15-20 hp. would be wasted.

 

[walleyehed]

Re: How big should my kicker be?

a 9.9-hp motor will push your boat as fast as a 30

However, what it can't handle are gusty or high head winds.

IMO, more than 15-20 hp. would be wasted. <br />

First quote is in no way true...I run a 7.5 and a 20 when I hit the big lakes. the 7.5 will push about 4-6MPH in 20MPH winds, the 20 will push anywhere from 8-12 MPH in the same conditions.<br />Second quote: the reason you want the 20-25 over a 9.9 or 15.....more thrust= more control.<br />Last quote: higher HP is only wasted if your main eng. NEVER quits when needed. Throttle back, if ya need it, ya got it. No rocket sceince in the choice here.

 

[Capn Mike]

Re: How big should my kicker be?

Walleyehead, I was abreviating my remarks because we've gone over and over this issue before. It's not rocket science: it's marine science. Sorry I didn't make myself more clear. All Formulafisher did was ask the time and I'm now going to explain how a clock works. <br /><br />The speed of boat @ displacement is based on the marine formula: boat length sq root X 1.3 = speed in knots X 1.2 = speed in mph. Doesn't matter if you're using 9.9 hp or 30 hp., a (say) 24' boat isn't going to go much faster than 8 mph. Period. WHILE IN DISPLACEMENT MODE. <br /><br />That's the formula. Of course, the formula doesn't take into consideration currents, wind, hull design or other factors. So while it might not take more than 5 hp to get my 24' Seaswirl at its maximum trolling speed, I still need more HP to control it better in those conditions mentioned above....mostly because, like most planing boats, it makes a lousy displacement boat.<br /><br />Lighter boats beat the displacement theory. Kayaks, well-designed canoes, some flat bottom boats and some catamarans go faster than they "should." Further, a jon boat, for example, is much easier to get on plane (or at least semi-plane/semi-displacement) than a deep V., thus the phenomena of jon boats planing @ 25 mph with 18 hp. <br /><br />Correspondingly, a well-designed heavier boat goes quite well with minimum horsepower. My 32' Grand Banks has 140 whole horsepower, and those retrofitted with 185 horsepower still aren't going to go faster than my 8-9 mph. The boat's gone quite well through 12-15' swells, 40-60 mph winds with that 140 hp and more horsepower would not have made any difference (the boat did better than I did...next time I trucked it from Portland to Seattle and back...I decided I'm not a Pacific Ocean kind of guy). The marinas are full of Kroegan, DeFever, Nordlund, etc. trawlers that go around the world with single diesels in what outboarders would consider ludicrously low horsepower because more would be just flat wasted horsepower.<br /><br />So how much of an engine should Formulafisher get? Oh, 9.9 to 20 should do it.

 

[walleyehed]

Re: How big should my kicker be?

I understand your thoughts on this issue, and I will respect that. My concern is controlability in adverse conditions and I stick to 5hp/1000lbs of boat for just that reason. In adverse situations, I've never once wished I had less hp than I did.

 

[Boatist]

Re: How big should my kicker be?

If your talking about a true displacement hull with a big keel I might agree with a lot of what been said. <br /><br />However in reality most planing hull have very little keel. My boat the kicker is mounted on a kicker bracket that has 15 inches of vertical travel and it is mounted on the port side. Steering is done with a EZ-Steer. Since the motor is on the port side it will turn faster to starboard than to port.<br /><br />Now if your headed into a large swell on the port bow and a strong wind on the same port bow then every swell will push the bow to starboard and the wind will also push the bow to starboard. Your kicker motor must be able to push the stern to starboard faster Than the sea and wind push the bow to starboard or you will have no control. At the same time need to have at least some headway.<br /><br />My boat a 21 runabout I limit it to swell less than 8 foot and over 8 seconds or we do not even launch. In summer almost every afternoon seas 4 to 7 feet and winds 20 plus knots with higher gusts. I tested my rig a lot of times and it is very hard to control in above conditions. Head way to next waypoint will be less than 2 mph on my boat. Down wind and down swell a lot different. <br /><br />One other factor is even though my motor has a 20 inch shaft and in the down postion will sometime go completely under a following swell, prop sometimes comes out of the water as a swells passes. In this condition must reduce the power to point the motor will not over rev and also when drops back in will not have such a shock that it breaks the flywheel sheer key. Either condition can leave you dead in the water. I changed to a bigger 4 blade flat high thrust prop and that has helped but still very marginal. I hope to be able to get a 20 HP 25 inch shaft 4 stroke for my 21 foot 2800lb pound Aluminum Runabout.<br /><br />Since condition almost always the same all summer long can plan trips to be in a good location to get in at the end of the trip on the kicker. Never had to do it for reel since I got this Boat in 1980.<br /><br />We fish out of Bodega Bay and have lots of friends with about the same set up as my boat and every one would like a bigger kicker if could get the weight down so can mount on a Kicker bracket.<br /><br />Anyhow this is how my boat works with a 15 HP kicker.