My review of the Cobra Magnum A.K series steering.

[Britboater]

After @Cobra Jet Steering LLC kindly included the A.K series in their winter sale, I purchased the kit for my new AR240.
I initially always wanted to fit this kit as the extra tie rod just looks so right, I'm on the fence as to whether Ali or composite is best for the fins. Jeff was very accommodating, easily contacted, delivery was on time and arrived well packaged.
To be honest, I was a little hesitant in posting my review as I had a few issues I wanted to clear up. Firstly, it was the S/S hardware supplied, I noticed the bolts were only A2 (304 or 18/8) quality, not A4, as I'd presumed, also the main bolt connecting the tie rods to the rudder was not a "shouldered" bolt, something I was very concerned about. Well, a big surprise to me, upon investigation the main bolts holding the jet pumps to the hull were only A2 S/S, in fact all hardware was only A2. Next, the rudder bolt I discovered, as fitted by Yamaha was not shouldered either!! My apologies to Jeff for doubting your product, but my concerns to Yamaha for fitting non-marine grade bolts and an ill fitting bolt to the rudder tie rod.

The kit includes easily read, clear instructions and the items are all identified with ease. Fitting only took 30 minutes, and that was me fitting from a toy boat floating behind the boat dock. I'd of liked a small tube of thread lock included with the kit. All items are metric (and there's me buying all imperial tools because I'm in the US ).

One note @Cobra Jet Steering LLC the small bolts holding the fins to the brackets needs to be a few mill longer as there not reaching the ny-lock nut.

A concern and warning to others fitting the kit, beware regarding the main rudder bolt, it seems Yamaha use non removal thread lock, or may be mine was cross threaded from the factory, I had a bitch of a job re-fitting the new bolt, and would not like to undo that bolt again. This is the factory bolt after removal.

Performance. I up-graded from a 190, IMO a single pump boat really needs fins, with my 240 and the rudder I was happy with slow speed manouvering, but with the canals and marinas I navigate I felt the cost, ease of fitment and look of the AK's a no-brainier.
Upon fitting I instantly notice a differance, you get an instant response now to your steering input, you can actually make the boat rock by turning the wheel left to right quickly. What I also noticed was how the fins compliment Yamahas TDE, if I push the buckets fully open in no-wake mode the steering response is instantly reduced. A big advantage with the fins is the ability to steer the boat while in "neutral".
Overall I'm extremely happy with my purchase and would recommend them to any owner of a post 2015 Yamaha owner, IMO three steering fins are more than enough for any boater, and as I've mentioned numerous times, it just looks so right, well done Jeff .

Note :- I have no connection to Cobra Jet Steering in any way and all my findings are from my own experience while fitting and using the Magnum A.K series steering kit.

 

[Julian]

@Britboater great write up! Thanks for sharing.

On a side note I would love for someone to get some empirical data for all the fins someday. Tests like the following:

• Before fins attached, boat in No Wake mode, no wind/current, mark a point on the shoreline and time how long it take the boat to complete a 360. Then do the same test with fins.
• the same test in idle speed
• Same test as above with boat No wake mode, switch to neutral, then turn (not sure it will make a 360 though)
• Perhaps same test with boat doing 15 mph, switch to neutral

So if someone buys this set, or any set for that matter....would be good to get some numbers (multiple) for these scenarios (anyone got others)?

 

[Gym]

Nice detailed review @Britboater.

 

[Glen]

@Britboater great write up! Thanks for sharing.

On a side note I would love for someone to get some empirical data for all the fins someday. Tests like the following:

• Before fins attached, boat in No Wake mode, no wind/current, mark a point on the shoreline and time how long it take the boat to complete a 360. Then do the same test with fins.
• the same test in idle speed
• Same test as above with boat No wake mode, switch to neutral, then turn (not sure it will make a 360 though)
• Perhaps same test with boat doing 15 mph, switch to neutral

So if someone buys this set, or any set for that matter....would be good to get some numbers (multiple) for these scenarios (anyone got others)?

Better than a shoreline reference point, it may be easier to be accurate with a fixed buoy or other anchored & floating reference point.
.02

BTW, gear from Cobra shipped this AM. Thanks @Britboater for sharing your experience-

 

[Julian]

Better than a shoreline reference point, it may be easier to be accurate with a fixed buoy or other anchored & floating reference point.
.02

BTW, gear from Cobra shipped this AM. Thanks @Britboater for sharing your experience-

Good point! Perhaps even using a GPS compass or plain old compass would work too?

 

[Murf'n'surf]

@Britboater great write up! Thanks for sharing.

On a side note I would love for someone to get some empirical data for all the fins someday. Tests like the following:

• Before fins attached, boat in No Wake mode, no wind/current, mark a point on the shoreline and time how long it take the boat to complete a 360. Then do the same test with fins.
• the same test in idle speed
• Same test as above with boat No wake mode, switch to neutral, then turn (not sure it will make a 360 though)
• Perhaps same test with boat doing 15 mph, switch to neutral

So if someone buys this set, or any set for that matter....would be good to get some numbers (multiple) for these scenarios (anyone got others)?

Overhead drone camera footage would rock.

 

[Cobra Jet Steering LLC]

In reviewing some of the previous posts from people who installed this system on their boat I have not seen anyone having any issues with removing the original factory bolt from the rudder, this leads me to believe you are probably correct that the bolt was cross threaded when the boat was built.
Here is a link to some of the previous posts about this system .
https://jetboaters.net/threads/cobr...m-a-k-steering-system.6093/page-2#post-116864
this system is not only about improving the steering at all speeds or is it just about allowing you to set the added effect, it is about balancing out the system, placing a push and pull on the rudder in either direction when you turn.
Evening out the wear and tear on the steering cables and nozzles etc.
This post shows a right side cable snapping for no apparent reason, I was also informed by a dealer that they were experiencing similar issues with the right side cable on the stock systems.
https://jetboaters.net/threads/on-the-water-and-lost-steering-on-starboard-engine.7631/#post-132157
To explain the lack of thread locking compound in the kit, Simply put, it is in violation of postal regulations .
I even tried the thread locking tape a few years ago . Thinking it would be the answer to the postal regulation dilemma only to learn that the tape degrades in heat , it can't be stored in a temperature exceeding 80 degrees. This was confirmed by the manufacturer.
I constantly received bad tape from my supplier so I finally decided to discontinue it as it was not reliable.
I do what the factory does and let you know you need to use it to be safe.
I am always amazed with people who can do an install of any system while floating in a small boat , it sure would not be something I would want to do, I would probably drop all my tools in the water.
I am glad that you impressed with the improved handling of the boat. I also agree that it looks impressive having the V configuration , not cluttered . Just a nice clean balanced appearance.