Irv
6/28/08 Post added to the first post for reference as this post is long and the added information from BCB would be smothered in between pages on Page 4 and not easily found by all readers.
We are going to add more to this as it seems to be an ongoing awareness.
There are no white lines on the water, though would you drive your SUV at 75 MPH on a TN or Arkansas swerving road? Nope not with any comfort and security of safety. And we are doing that on the water without white lines, without knowing if there is a 3' to 4' pot hole around the next bend. Below we will attribute much of this on the ponies we all have today and our desire to use them.
There have been many incidences in the recent 24 months and we definitely think there are plenty of different factors. Not one scenario seems to have been replicated in different incidences. There seem to have been incidences of fatality in some of these situations this year, and luckily not of/in the BCB "Family". Though errors are awry in all the incidences. Note we said errors in all of the incidences. Those errors all being different again. The only common error is excessive engine height, and we will get to that, and another is a smaller propeller diameter or square inches of bite face.
A. Phil pointed out a good understanding of this. We have more torque with the popularity of the big 250 engines now. There are now more 250's than ever before. The ratio in our boat was once very small and more inclined to the individuals who are most experienced. The 250 VX Yamaha in a carb. version was not the same. It did not have as much "poot". And the 250XS was as limited production engine with a short Warranty, which kept the popularity down considerably. You had to want to go fast and desire it, which means you probably had more "seat time". Or you wanted it as a symbol of performance and almost never used it.
This was not frequent with 225, 200 and 150 engines. Only under conditions mentioned below that were extreme. The 250's have brought this to a more common occurrance. And you all want those 250 engines, though you do have to learn to respect them more just like your SUV on that country road. And a county road in Arkansas or TN is not a farm CR flat space in OK or TX. Think snakes back, ok, Sears Point or Sonoma, maybe Lime Rock.
B. Next in the equation is a Hydraulic Jack Plate, which we really have not ever suggested HJP's for the average anglers. That is a factor one tends to want to play with and it can really complicate things in many scenarios. They leave them up after running a flat and when they turn into a creek channel the skeg is up and there is no rudder (skeg) and the boats slide and slip sideways, occasionally landing in a marsh, tree forest or if you are lucky a sandbar.
C. The other factor in excessive engine heights are wakes/waves, which launch the hull and leave the propeller on top of a wake or wave at an almost parallel angle. That holds the hull out over the trough while the tial or pad rides the wave/wake, though the propeller is now reaching a loss of bite in the trailing trough. As the propeller reaches a right hand wave/wake, the blades are now touching the side surface to the right of that water column. Though the skeg is not into the water medium yet. Thus the propeller goes loose feeling, as if the bite is lost. Though the bite is actually increased, only to one side. Though the skeg is not in play and the side play of the propeller is enhanced driving the boat to the right, and stern to the left. Which can get quite radical in a hurry. This is not a hook, though a stop by opposing forces as the hull catches the peak of the wave. The torque is a factor in two actions the left spiral, while more so only one factor in the right spiral. The torque in the right is from power, whereas a left can be more from reduced torque/power (D.) and sometimes less frequently torque loading.
This is more common on lefts, though much more radical on rights.
Not always is this only a wave factor, it is also a propeller bite issue on sweeping corners with loads. The propeller can loose bite, especially if high, and the hull will slowly let down by tenths of a second, and then the bite releases more on the tailing propeller. The result of driving too hard in this situation is a spin out and no different than loosing a vehicle in a corner. You screwed up, though now you have to deal with it.
. This can also be enhanced by a small propeller diameter, or increased interior and reduced exterior propeller blade surface. As the propeller is loosing lower blade bite on the oscillation which actually assists in controlling the hull. Which is why we prefer large surface area propellers, and not the ones that some companies and folks recommend. We think the Fury is a good wheel for folks starting out. It may have other applications as well. There are some motor company propellers that we are not fond of at all. And again all hulls and setups are different. Both within a model and brands definition, as well as within a size category and weight. Though longer and heavier boats with more ponies are the most frequent.
E. Hot Foot's come into play (which we don't recommend) on the reduction in the loading often comes when the propeller gains that loose feeling as the hull is cresting a wave the reduction in engine torque perplexes your brain, and you immediately back off the throttle. Oops' made a mistake there, as the hull now falls, bites, the propeller now brakes and the entire process of torque is either released or reversed. In other words all "XYZ" breaks loose. Don't bakc off, trim down as often as you can and try to keep that pressure on the blades and keep the propeller driving forwards. Always trim before releasing if you can. Realizing emergency situations are all different.
F. Next is boat weight as we all have to have more gear. We added batteries(y), larger batteries, more fuel, more goods, more storage, larger trolling motors, just overall more! Folks forget the forces that make 4,000 pounds of boat, motor, gear, and people to go at 75 mph in water, a liquid medium, are rather groaning. Yes there are large torque loadings goin' on!
1. Now a Mercury 250 Pro XS, VZ250 Yamaha and the 250 HO Evinrude today are all VERY STRONG engines. They appear to be producing more raw torque than previous engines. The propellers are developed and things are changing in all circles. With that gain in ponies, torque, propellers, hydraulic jack plates, hull and more is probably one of the most major learning curves. As we seem to have eclipsed the abilities of some folks. Really a 225 is not nearly as susceptible.
H.You folks want more fuel efficient and free running hulls to gain fuel mileage and enhancing the smoother ride, such as we delivered last season on the '08 model Puma and Cougar FTD hull. Other competitors are also reaching out trying to improve to meet us, they also are improving. Some have a ways to go, though they are getting better, and so must we. In 2009 we will improve performance again, and we will keep trying to do that in 2010 and every year going forward.
I. Last is the Hamby, or Keel Guard, and yes we think they definitely have a very large impact. The Hamby can hang into the water as much as almost an Inch (1") and most are around 13/16", just in case you want to know. That is a huge force on the bow to grab in a corner and it can act as a pivot point when it increases drag at the right angle, torque and grab situations. While some of us run a Hamby for the hull protection, we are very aware of how it impacts the performance. We compare it to sticking a disc brake puck in a hull, press it down when you want to turn, and release it when you want to go straight. That Hamby is no different if it contacts just right.
Actually the disc brake thing was outlawed almost 5 decades (50 years) ago when Lewis put them in his hull outer flats to turn corners. Entering a corner he would engage the brake caliper pucks, and mid exit he would release them. The result was pinning the buoys and he went from getting challenged to winning every race till they figured it out. Which didn't take long and the race officials outlawed it.
In closure, we now have visited a host of factors that enhance the concerns. This is a worthy read to keep close at hand, though it only mentions a fraction of the most common scenarios one could expect. The variables are many and we want all to be safe as you all know.
Ask yourself, Would you give your 16 year old son the keys to your Cougar FTD with a 250 Pro XS, and turn them loose? We won't and our sons were raised driving them. Sometimes folks forget and act as if we are 16 again in the heat of take off, as adrenaline is pumping through our veins they press harder. Till something gives, and the result we hope is not catastrophic. Though with a read like this, you will learn to take a pass differently, look for a wave more, and try to understand what a hydraulic plate gained popularity for. Not to add a 1/2 mph to the top end. To get you where the fish are when you need to idle a long ways.
We hope this descriptive helps someone to understand what is happening and how many variables there are for powering a rig.
Sorry to be so lengthy, though we wanted to give you some answers and some thoughts to ponder on~!






