Kicker Advice

[Max123]

Looking for some advice on selecting a kicker for my boat.

I have an 18ft aluminum centre console (20ft overall with pod/hull extension). I use it mainly for pleasure up in Pitt Lake, and we typically take a few friends with kids as well. Last year I had two cases where the motor wouldn't start at the end of the day - completely dead, and then mysteriously started after about a minute of fussing around. The issue appears to be resolved with a new starter solenoid, and hasn't come back. In spite of carrying around all the typical tools, jump pack, radio, etc - it made me realize I'm not comfortable with having a single point of failure and needed a backup for my own peace of mind.

Anyway, I'm having the transom modified to add a bracket, and I plan on buying a kicker as a failsafe. It would just be a pull start, tiller steering and run on its own separate fuel tank to keep everything completely separate from the main. Bare bones setup - if this thing never gets used, I'll be happy. Doesn't need to be the quietest, smoothest, prettiest or most powerful - it just needs to get us back. Ideally light and easily removable, so I can store it and not worry about theft.

A +100lbs 9.9hp kicker is not really an option based on my transom and the weight balance of the boat. However, I think a 6hp should get me up to hull speed and most seem to to be in the 55-60lbs range.

If you search online the consensus is that all 6hp kickers are basically the same, but that doesn't seem to be the case at all once you get into the spec. For my application, I think I need a high thrust gear ratio, low pitch / large diameter prop, whereas most of these motors are setup for powering around little tenders.

Here's what I found:
Suzuki DF6: 55lbs / 138cc / gearing = 1.92:1 / 3-blade 7.5" diameter x 6" pitch
Yamaha F6: 60lbs / 139cc / gearing = 2.08:1 / seems like standard prop is similar to suzuki, but the internet leads me to believe it 'may' swing a bigger 9" diameter prop
Tohatsu MFS6 'Sailpro': 57lbs / gearing = 2.15:1 / 8.3" diameter x 6" pitch (high thrust prop)

Prior to doing any research, I was thinking of a Suzuki - but this seems like its more setup for a small tender (geared for speed) and as far as I can tell there are no aftermarket/high thrust prop options. The yamaha seems like it 'could' be ok with the better gearing, but only if I can get a larger prop and that seems unclear. The sailpro seem to tick all the boxes, but I've never owned one.

Anyway, always appreciate the knowledgable feedback.

 

[Max123]

Here's the proposed kicker bracket setup. Bit weird due to the rounded swim grid. Will be 1/4" aluminum plate. The tie down eye will get moved further out. I wanted something that looked like it was part of the original build.

 

[Pineapple Express]

When I was reading your post I only got about halfway before I thought "he needs a Tohatsu 6hp sailpro" and then there it was in your choices list.

 

[Brando]

That tie down is in a really weird spot and should be moved anyways the material has very little strength being pulled at that angle. Your bracket design looks sound. I would probably make the plate a bit longer vertically and it will need to be thicker at the top for the motor to clamp on if you’re not bolting it so keep that in mind. Can always add some uhmw/starboard to either side of the plate to add some thickness or have the fabricator use a bit of tubing at the top or box it in.

 

[Max123]

That tie down is in a really weird spot and should be moved anyways the material has very little strength being pulled at that angle. Your bracket design looks sound. I would probably make the plate a bit longer vertically and it will need to be thicker at the top for the motor to clamp on if you’re not bolting it so keep that in mind. Can always add some uhmw/starboard to either side of the plate to add some thickness or have the fabricator use a bit of tubing at the top or box it in.

Thanks for the feedback. The loop is actually a towing eye (there is another one on the opposite side). Definitely not ideal as a trailer tie down, but works well for towing other boats, or kids in a tube. Once these get cut off, I'm going to install two beefy stainless U-bolts on either side of the main.

The kicker bracket will be an extension off the side of the transom made from 1/4" flat plate, but will have a 2x2 square tube along the top to match up with the original transom. This provides a total 2-1/4" thickness at the top. The bracket will extend down 6".

I based the dimensions on a Suzuki Diagram for the DF6. All the other manufacturers have garbage drawings with no detailed dimensions. The Suzuki clamps work up to a 2.5" thick transom, and the transom tilt bracket is 5.6" - so a 6" tall bracket should be fine. I'm 'assuming' this is a fairly standard size.

The 6hp kickers seem to use small transom brackets. Its only once you get into something with power tilt that you need a huge bracket.

 

[Brando]

Towing eye makes more sense. Good luck with the project sounds like you have done your homework.

 

[Aquaholic]

I like that you are trying to keep your kicker "inline" on the same transom lip extension as the main motor. I have a similar set up, and the single tie rod attachment is a thing of simplistic beauty. My kicker (9.9) is also a manual pull, manual tilt etc. and it works very well. Plus there is no after-thought arm sticking out to attach a kicker to, you can make this look like an original plan.

Why not run another line off your fuel filter for the kicker fuel supply? Is the main a 2 stoke? A separate tank really seems a way to take up limited space on an 18' boat.

 

[Max123]

I like that you are trying to keep your kicker "inline" on the same transom lip extension as the main motor. I have a similar set up, and the single tie rod attachment is a thing of simplistic beauty. My kicker (9.9) is also a manual pull, manual tilt etc. and it works very well. Plus there is no after-thought arm sticking out to attach a kicker to, you can make this look like an original plan.

Why not run another line off your fuel filter for the kicker fuel supply? Is the main a 2 stoke? A separate tank really seems a way to take up limited space on an 18' boat.

Running the kicker off the main fuel tank is tempting, but here was my thinking:

- I've heard that a lot of fuel issues come from kicker tie-ins. Either the kicker fuel pump isn't strong enough to suck all the way from the tank and deal with the pressure drop on the remote fuel filter. Also, more fittings = more risk of air getting in. These issues are likely solveable by ensuring the Racor is sized correctly, and adding isolation valves to the main & kicker feeds.

All that said, the original through-hull fittings for the main are a thing of beauty. Fuel/controls/hydraulics all come through the transom in a beautiful little welded box with proper water tight connections/hoses, etc. I don't want to hack it up with a separate connection that i'm not happy with. My rule is that everything needs to be done to the same level as the original build. When in doubt, wait and think about it a bit more till you can plan out a solution. In the meantime A small 2 gallon fuel tank can stay hidden inside, and then I just pull it out and connect as/if needed. Every few runs, I'll dump the remote tank into the main to ensure fresh fuel. Also nice to have a spare few gallons handy in case you run into a boater marooned with an empty tank.

 

[Adrenafin]

I would mount the kicker on the port side personally to offset weight. I like having separate fuel supply for my kicker. Reason being if your fuel system gets contaminated(water) or leaks your still getting back to the dock.

 

[Max123]

I would mount the kicker on the port side personally to offset weight. I like having separate fuel supply for my kicker. Reason being if your fuel system gets contaminated(water) or leaks your still getting back to the dock.

I would, however I have a ladder + transom door on port side already so that wasn't an option. I realize my setup isn't ideal because it puts the kicker tiller handle next to the main, which could limit the full range of movement. That said, battery is on the port side, so hopefully the weight cancels out.

Appreciate the feedback.

 

[Adrenafin]

Invest in a tie bar that connects with your mains steering then you can just put the tiller arm straight up and out of the way. Good luck.

 

[Max123]

Would you do that without also doing remote throttle control? I'm not going anywhere fast, so don't see a ton of risk, and huge benefit of being able to steer better. Will likely investigate this.

 

[Aquaholic]

Would you do that without also doing remote throttle control? I'm not going anywhere fast, so don't see a ton of risk, and huge benefit of being able to steer better. Will likely investigate this.

I currently tweak mine by hand while trolling, tiller in vertical position, but a Troll Control or ITroll would be nice.

 

[Max123]

Anyone know the typical max transom thickness for small outboards. I'm getting conflicting information. Suzuki shows 2.6" but unclear if that includes the cone washers. None of the other manufacturers even list this in their drawings. Casting around on the internet, seems like there is a bit of variance. When I talked to one of the dealers, he recommended 2", and said 2-1/4" would be pushing it for some manufacturers. Some also include little ridges in the bracket to help it seat into the wood transom - whereas my 1/4" plating isn't going to compress at all.

I was originally going to do 2-1/4" to match the existing, but may need to take it down to 2" to be safe and clear the clamp bolts.

Annoying - I'd rather just bolt it up, but I think these small outboards typically only have two mounting bolt holes in addition to the clamps.

Edit: Tohatsu has fairly crap literature, but was able to dig up an old mercury rigging manual which shows transom clamp w/ washers fully open at only 2-1/16". A yamaha rigging manual shows 2.3" fully open. Likely going to cut down to a 2" transom.

 

[brutus]

Anyone know the typical max transom thickness for small outboards. I'm getting conflicting information. Suzuki shows 2.6" but unclear if that includes the cone washers. None of the other manufacturers even list this in their drawings. Casting around on the internet, seems like there is a bit of variance. When I talked to one of the dealers, he recommended 2", and said 2-1/4" would be pushing it for some manufacturers. Some also include little ridges in the bracket to help it seat into the wood transom - whereas my 1/4" plating isn't going to compress at all.

I was originally going to do 2-1/4" to match the existing, but may need to take it down to 2" to be safe and clear the clamp bolts.

Annoying - I'd rather just bolt it up, but I think these small outboards typically only have two mounting bolt holes in addition to the clamps.

Edit: Tohatsu has fairly crap literature, but was able to dig up an old mercury rigging manual which shows transom clamp w/ washers fully open at only 2-1/16". A yamaha rigging manual shows 2.3" fully open. Likely going to cut down to a 2" transom.

2” for small outboards, with mine I just drill holes and bolt them on, have had a few stolen over the years, one with a lock on the clamps, they just cut the clamp

 

[Max123]

Thanks for the advice everyone, boat is out at the welders now. Modified the bracket slightly to suit a 2" clamp. Also having proper trailer tie downs welded on.

Will post a photo of the finished work when I get it back. Then off to buy a kicker...

 

[Max123]

Here's the update - Kicker bracket installed. Purchase of a kicker still pending.

Welding was done by Tom at Tommycraft marine in Maple Ridge. Stand up guy, everything turned out as good or better than expected. I won't share the exact cost, but I thought it was totally reasonable. More importantly, no unpleasant surprises when I picked it up.

So, based on the advice of the welder (and points noted here) we made a few final changes. It wasn't feasible to just extend the original engine bracket in the same profile. The original top tube is 2x2 + 1/4" flat plate and the 2-1/4" x 2 profile just doesn't work for small kickers for a variety of reasons. So the idea of making the extension look 100% factory just wasn't a good idea and a more rectangular profile was required. Likewise, we changed the brace slightly to better match the overall profiles/angles of the boat. The brace is coped slighly so that it is tied into the perimeter round tub as well as the floor of the swim grid. The whole arrangement is rock solid with zero flex. Tom also added two tie downs on the underside of the swim grid for my trailer tie-downs (visible in the second photo).

Overall, pretty happy with it. I just need to add two stainless U-bolts on either side of the main for towing - which I prefer to do myself.

 

[Max123]

Main engine is a 25" XL. For the kicker was thinking a 20" long shaft would be fine with the narrow pod. A 15" short shaft would be ideal for compact/storage, but seems like I'd likely risk losing traction in rough water.

 

[noluck]

looks nice but the mounting plate is not long enough to support the entire engine and the thrust of the engine pushes on the bottom

 

[Pineapple Express]

looks nice but the mounting plate is not long enough to support the entire engine and the thrust of the engine pushes on the bottom

The fabrication looks top-notch, but I agree that the new part for the kicker doesn't go low enough to support the full height of the kicker's transom bracket. Potentially you could mitigate this by through-bolting the kicker (like the way the main is mounted) rather than using the screw clamps.