Kicker size?

Time

Time

Well-Known Member
Just a question on how to size a kicker motor.
I'm quite happy with my T-8 as I also was with the previous F-8, and probably something smaller would have sufficed, but I see a lot of other boats equipped with 10 (9.9), 15, or even 20 hp kickers.
Just wondering how one should select a kicker.

Max boat speed is, I vaguely recall, a function of something measured against the wetted hull length.
Just wondering if buyers are being oversold on size of kicker motors. Or how to select appropriate siize?
 
How long and heavy is the boat...my general rule of thumb is up to 20 feet 8hp is fine, 22 to 28 feet 9.9hp, above 28ft- 15hp and up.
 
IMO it depends on what you what to do with your kicker. If you just want to troll with it then a 8-9.9 hp will work for most boats up to 26 ft. If you want to use it as a back up engine you may want to go with more HP to get faster speed depending on where you fish. For example if you fish the banks and you are 30 miles offshore and the weather starts getting nasty you will appreciate the extra speed that a 20-30hp kicker gives you. If you fish mostly inshore a 8 or 9.9 hp is fine. Remember most sailboats under 30 ft., that usually weigh more than same size power boats, use 9.9's for their engines. My 2 bits.
 
The only item I'd add to the above is if you are fishing in areas where there can be a very strong tidal current then the extra horsepower can mean the difference between making it home at 5mph or 1mph.

A bonus about the 8hps is they are usually lighter than the 9.9s. And the 9.9s often have the same block size and weight as the 15s so the choice between a 9.9 and 15 is more about upfront cost and fuel consumption.

I used to run a johnson 8 on a HEAVY 20ft boat as a kicker and it always had enough power to bring me home. But the same setup if I had to return up the fraser on a strong outgoing tide having a 9.9 or 15 would have been nice.
 
I have owned both a 8HT Honda and now a 9.9HT Yamaha. The first on and 18 Malibu and the second on a 21 Striper. Both are more than enough to push a boat in all conditions for me. Yes it could be a 4 hour ride back from the bank but that is worst case scenerio for sure. If I was that worried about that happening then twins would be on my boat. Many good points have been made as to the reasoning behind picking a kicker so I will give the main reason I would buy a HT regardless if it is an 8 or 9.9. For me it came down to the charging system that is on HT"s compared to a regular 8 or 9.9. To me the kicker is used for trolling and for emergency use obviously if the main craters. It also is for maintaining my batteries that can take a beating somedays depending on what you are doing. At low revs with a smaller charging system you would be suprised that you don't quite keep up with demand on a busy day.......deep water trolling.....prawn pullers etc.....Just my two cents!
 
I put a 15 on my boat. It's my backup power as well. If my main breaks down I want to get in a little quicker.

Dave
 
The size of a kicker should be based on the weight and profile of the boat. A sailboat is heavy, has a deep draft, and has very little wind profile. With the little wind profile, they only need thrust to move that weight and enough horsepower to obtain the desired speed.

A 12,000 pound, high profile fishing boat (think those 16 foot high wind catching fly bridges), with 3 foot draft need thrust to move them; however, they also need horsepower to control in winds. A 9.9 HT provides the thrust, but does NOT provide adequate horsepower. The thrust provided will be fine, until you find yourself in winds. I would suggest looking at enough horsepower to control the boat in winds - either a 15 or 20 HP.

Most sport fishing boats fall in the category where they are light, little draft, and have low profiles. These really don’t need addition thrust, as thrust means moving weight. They do need horsepower to get the intended job done. Those 8-10 HP kickers are usually more than adequate, will work just fine, and they cost less. But hey, I have made the same mistake myself confusing the need for thrust and the need for horsepower. :)

You can get charging units for most kickers that increase what comes from the factory. If one is looking for more than 6 AMPS @ W.O.T. from any manufacture on anything below 15 HP, look Honda. Their 9.9 “electric start” produces 12 AMPS; however, keep in mind their manual start still produces that 6 AMPS.
http://marine.honda.com/Products/modeldetail/BF9.9

From the factory the Yamaha output @ W.O.T. on anything under 15 HP, including the9.9 HT is 6 AMP. When you go to 15 HP the Yamaha goes to 10 AMP.
http://www.yamaha-motor.com/outboard/products/subcatspecs/5/specs.aspx

On Mercury 9.9 HT (Bigfoot) output is also 6 AMP, theirs goes to 12 AMP on 15 HP and above.
http://www.mercurymarine.com/engines/outboards/fourstrokes/15/
 
Hate to disagree with you Charlie, cause I know your almost always right. The table you posted is for the F9.9. I'm pretty sure the HT 9.9 outputs 10 amps.
 
TheBigGuy said:
Hate to disagree with you Charlie, cause I know your almost always right. The table you posted is for the F9.9. I'm pretty sure the HT 9.9 outputs 10 amps.
Click to expand...
Hey... I am okay with that... 100%! Can you show me where you are getting those spec? :)
 
TheBigGuy said:
Yamaha owners manual. Online version won't let me copy and paste -copy protected.

http://www.yamaha-motor.com/outboard/service/viewmanual.aspx?ls=outboard&yr=1&lid=5&mid=1410


look under maintenance section:

Alternator output for battery DC:

F9.9EH 6.0 A
T9.9EH 10.0 A
T9.9ER 10.0 A

You had me going for a second there Charlie, that was a ***** to find.
Click to expand...

That's okay, I hate to tell you this my friend, but... you have, and are looking at a 2006 owner's manual! If you want to go back just a few more years, you will find some that have 15 AMPS. How old do we want to go? I believe, the one's being produced now only have 6 AMPS, am I wrong? :)
 
You may be right Charlie, but mines a 2009, and I was pretty sure it was 10 Amps. That is the guide directly off the Yamaha website for all T9.9 years 2006 or later. Maybe they need to update their website more often. I guess newer doesn't necessarily mean better does it.
 
Haha... you might be right also! 10 AMPS was and is an option that can be istalled! :)

In the past, many 9.9 HT kickers actually did produce more AMPS as they were/are built on the higher HP frames. The 9.9 comes into and is from the horsepower rating @ the prop. There is NO doubt in my mind there are 9.9 kickers out there that have more than 6 AMPS (just look at and think Honda there), some even have 15 AMP charging systems. Just about any kicker can be adapted to produce more AMPS! However, I kind of, have to believe the current manufacture specification sheets! There is NO doubt in my simple mind there is NO Yamaha T9.9 High Thrust (or Mercury Bigfoot) that "currently" comes "standard" from the factory with a charging system above 6 AMPS. Now, that is NOT saying they don't exist, nor that there is or isn’t options that can be purchased, as I also know there are!

Yamaha High Thrust T9.9 - right from the factory specifications:
Alternator Output @ W.O.T. 6A
http://www.yamaha-motor.com/outboard/products/subcatspecs/4/specs.aspx

Hey, but what do I know! I am just some dumb "know it all Yank"!! :D
 
Last edited by a moderator:
I'll take you're word for it Charlie.

Things change, just goes to show that you can't assume anything these days. Manufacturers are all trying to reduce costs and improve profit margins. Guess it's another case of buyer beware, make sure you're getting what you want before you drop the cash.
 
TheBigGuy said:
You may be right Charlie, but mines a 2009, and I was pretty sure it was 10 Amps. That is the guide directly off the Yamaha website for all T9.9 years 2006 or later. Maybe they need to update their website more often. I guess newer doesn't necessarily mean better does it.
Click to expand...

I have the 2009 as well......the same model that they decreased their overall size and weight as well. It definitely has a 10AMP charging system on it? I had my meter on it and did some testing on it to see how much the revs affected the output of the alternator. The highest current I saw was 9.8 Amps......close enough! lol I did order it in from the dealer and didn't have any special mods made to it? I made sure on the 10 Amp system before I bought the Yamaha since I had the 03 Honda HT before this one? Not adding gas to the fire or anything......but that's what I have......maybe a one of???
 
Last edited by a moderator:
The other consideration I'd make when selecting a kicker is getting one with a pull-start option as well as electric. Protects you against catastrophic electrical failure (e.g. both batteries dead -- been there....).

I used Charlie's advise when I got a new kicker for my 288. I picked a 20Hp Tohatsu with the High Thrust prop option. Same displacement and weight as the 15Hp. Has a 12A alternator plus a pull start. In a strong wind my boat gets blown around pretty good, and this engine can turn it and get it headed in the right direction.

PS: formula for calculating the hull speed of your boat is SquareRoot of waterline x 1.34 -- so the hull speed of a boat with a 28ft length at the waterline is ~7kts.
 
Last edited by a moderator:
Hi Gypseas.

The problem is Yamaha has conflicting specs on their website. See my earlier post regarding the owners manual on their site. So, if you want a 10 amp charger, i guess it's not standard anymore. Make sure you findout before you purchase. If upgrading to !0 Amps is optional I would highly recommend it. Especially if you're like me and want the stereo, full electronics, and electric riggers.

Hey tenmile.

My Yami HT 9.9 doesn't have the pull start. Initially I was a little nervous about that. Then i rembered in all my years on the water, I've never drained both batteries so bad that I couldn't start my kicker. You can always start it by removing the cowling and using the emergency pull cord. Definitely a pain, but it is only for backup

I realized this can be used to my advantage, I converted my starting system so that I could shut off the power and lock it off. A little extra theft deterrent at the marina never hurts. Anybody can just jump in most boats start the kicker and motor away. Some guys did exactly that a couple of years ago when I was at China Creek. They also took about 20 other electric down riggers with them. Luckily, I wasn't hit that night. After that I realized, better to make your boat a little harder to steal.
 
You must log in or register to reply here.

Similar threads

M
Kicker Tie Bar - Liquid vs Mechanical
Replies
4
Views
1K
russellfergus
R
S
Help first time buying used boat.
Replies
9
Views
2K
Shineyshiney
S
Sharphooks
12V Battery Management: Seastar EPS—Electric Steering Actuators
Replies
7
Views
876
Sharphooks
Sharphooks
W
Merc Kicker Question.
Replies
7
Views
791
noluck
noluck
JohnN
Will A Kicker Fit
Replies
4
Views
550
sasqman
sasqman
Back
Top