It may be time to refresh the MAGNUM A K system information for the benefit of the new members.
When Yamaha first came out with the twin engine 24 foot articulating keel . I identified several areas that I felt could be improve on.
First when you take a jet boat and build a large keel under it you change the handling considerably to the point the boat wants to go in a straight line and the faster you go the more it wants to go straight, thus resisting turning as quickly as a non keel hull.
Adding a rudder in the center of the boat behind the large keel partially shielded it , this shielding keeps the rudder from having immediate influence on the hulls direction.
Obviously the rudder also has a large amount of force being applied to it being applied to the right hand nozzle and steering cable ONLY!
For some reason the steering cables were reported to be failing and at one point they were unavailable on backorder last year if I recall correctly. Perhaps this was a direct effect of the imbalanced steering input from only one side of the helm.
Next was the helm itself, I am guessing with a large amount of certainty that the helm was changed to reduce the increased amount of steering resistance felt in the wheel by the operator during high speed turns due to the resistance from the large rudder .
This was my conclusion because the steering travel was doubled. Simply put it was geared down , the original steering wheel on Yamaha jet boats would travel from 12 o'clock to 3 o'clock for a full right turn and from 12 o'clock to 9 o'clock for a full left turn, Now with the new helm the distance for a full turn is from 12 o'clock to 6 o'clock both ways. Unfortunately this also reduces the response ratio of the steering from the helm . So A large boat with a large rudder needs more input from the steering system at all speeds. This system also could use a second tie rod to balance out all the work load and create redundancy if one side ever failed.
So The magnum A K system was designed and first introduced here in June of 2015
https://jetboaters.net/threads/cobr...wing-you-the-magnum-a-k-steering-system.6093/
Since then this system has become very popular for obvious reasons.
I then began designing FANGS for the ultimate and regular Magnum steering systems, and decided to make a simple inexpensive add on set of fangs for the Magnum A K steering, the fangs are smaller fins that create power steering by placing some fin surface ahead of the pivot point on the fins this catches the force of the water traveling past it ant the water turns the steering for you, and that also reduces the real force applied to the steering components. Yea pretty good but that is NOT ALL as they say. because the Yamaha nozzle is so different than other nozzles, The water for reverse shoots out from under the nozzle toward the front of the boat, this is accomplished by having a second opening under the nozzle and a reverse door come down and close the regular water exit opening of the nozzle forcing the water out the bottom. However the water fans out pretty quickly. The fang is along side the opening and it helps to direct the water under the boat keeping the thrust aimed better and the extra fin surface helps as well. So you now have more control in reverse than a stock boat although you still have to deal with the keel resisting the boat turning.
There are many people on this web page that have this system added to their boats with great results, the price and the 30 day guarantee is also inviting and I know it has been forever but I have personally been holding a model 19 to the head of my son in law to get the new web page finished, his kidney transplant went great and he is now working on it diligently " so he says" we shall see. Any questions feel free to email me if you like
jeff@cobrajetsteering.com 15 years experience making jet propelled watercraft steer 3 us patents and another pending, if you are not smiling when you drive your jet boat you probably don't have COPBRA JET STEERING.
