The Game Changer and chine walking

[kramr]

Have a new PIV with the Yamaha 200 SHO motor and Im just getting it broken in and learning to drive it. I havent been fast enough yet to experience chine walk but I have been reading as much about it as I can so I will be prepared when it does occur. From what I have read, chine walk is the effect of torque from the motor causing the boat to fall off of the pad in the same direction as the motor is turning. From what I know about torque is that the larger the displacement the more torque the motor produces. Most of the other 200 hp motors out there are 2.5 – 3 liters. The SHO is 4.2. Wont the SHO produce more torque and therefore increase the severity of chine walking? Ive looked on the website for torque figures and couldnt find any so I cant say for sure about how much more torque the SHO produces but my knowledge of automotive motors tells me it should be a lot more.

[Bass Cat Boats]

From my experience with the PIV and a 200 Opti very little chine walk occurs with that hull. Very easy to drive and limited driver input is required. Especially with a full load and two people. Interested to see how the SHO runs on that hull. My understanding is that the SHO will like to be run high on the plate.

[Bass Cat Boats]

kramr,We think you are not right in your opinion. There are many injections on “chine walk” and we think most of them are wrong, very wrong actually. Most opinions are not by qualified individuals, though people simply trying to help without realizing what is happening. There is no “chine” in the process at all. It has little to nothing to do with the chines of a hull, or the engine torque itself. From what I have read, chine walk is the effect of torque from the motor causing the boat to fall off of the pad in the same direction as the motor is turning.Chine walk is oscillation of the propeller in the water, and torque of the blade. The issue is flex of motor mounts and water that is not a solid medium. Thus the propeller tries to pull the engine to one side and the engine mounts flex, then pressuring the engine back the other direction. The key is to learn to balance those pressures. Keeping the trim down, and practice never letting the nose of the boat go to the right to balance the sway. Keep the nose left, and trim up as you learn to drive. We know this is a new experience for you, though please dont over indulge your learning curve with inaccurate information. Take your time and work your way up on the trim and throttle and you will be fine. Just take it a bit slower than you probably want to. bama96 is right in that a P4 is not prone to much chine walk. It can, though not too bad from our experiences. BCB

[kramr]

Bama96 wrote: From my experience with the PIV and a 200 Opti very little chine walk occurs with that hull. Very easy to drive and limited driver input is required. Especially with a full load and two people. Interested to see how the SHO runs on that hull. My understanding is that the SHO will like to be run high on the plate.I have leveled the boat and motor and measured from the bottom of the pad to the floor and the center of the prop shaft to the floor. The difference was 5 inches. So is the motor 5 inches below pad? Doesnt sound like it is sitting high on the plate but maybe were talking about 2 different things. This was how it came from BCB. I figure they would know a lot more about how it should be set up than me.

[kramr]

Bass Cat Boats wrote: kramr,We think you are not right in your opinion. There are many injections on “chine walk” and we think most of them are wrong, very wrong actually. Most opinions are not by qualified individuals, though people simply trying to help without realizing what is happening. There is no “chine” in the process at all. It has little to nothing to do with the chines of a hull, or the engine torque itself. From what I have read, chine walk is the effect of torque from the motor causing the boat to fall off of the pad in the same direction as the motor is turning.Chine walk is oscillation of the propeller in the water, and torque of the blade. The issue is flex of motor mounts and water that is not a solid medium. Thus the propeller tries to pull the engine to one side and the engine mounts flex, then pressuring the engine back the other direction. The key is to learn to balance those pressures. Keeping the trim down, and practice never letting the nose of the boat go to the right to balance the sway. Keep the nose left, and trim up as you learn to drive. We know this is a new experience for you, though please dont over indulge your learning curve with inaccurate information. Take your time and work your way up on the trim and throttle and you will be fine. Just take it a bit slower than you probably want to. bama96 is right in that a P4 is not prone to much chine walk. It can, though not too bad from our experiences. BCBThanks for educating me on a topic with more opinions than facts.What do you think the top end will be with this boat/motor combination? Last edited by kramr on April 26th, 2010, 2:22 pm, edited 1 time in total.

[jcdogfish]

I never knew what causes it, but I know what helps it. Engine height, wrong prop or style of prop, weight distribution and Im sure a few other things (like a finger always on the trim button) all contribute to making it better or worse. Im old school so I actually find it easier to drive a properly set up boat with cable steering. I find it harder to feel what the boat is doing with hydraulic steering but Im sure thats just me and what I am used to. One thing for sure,,If the walk is getting worse dont try to drive through it. Just take it in small steps and you will get it soon. I cringe when I hear people say you have to drive through chine walk. The key is to keep it under control from the beginning. An experienced person can straighten out a boat that is walking and getting worse, but an inexperienced person can only get in more trouble. When I sold one of my overpowered, short boats in the late 80s the person buying it was not used to driving that fast. In his test drive I would have to reach over grab the wheel and calm it down for him. I spent a lot of time letting him put the boat in a slight left hand turn when it got crazy to get the feel of what he needed to do. He bought the boat and wrecked it 3 weeks later. The person with him was showing him how to drive through chine walk. From my experiences with a BassCat, if it is set up properly, with a little guidance you should be fine in a few trips. If you are experienced you wont know it is there. I would suggest an inexperienced person drive the boat with the factory setup for a while, get comfortable with it before you start jacking around with engine heights and props etc.

[mike dominick]

Kramr, I just got my 09 PIV a couple months ago and have only had it in the water about 6 times, I had scary chine walking the first few times out while trying to figure out the setup. I moved the motor up till I had a little steering torque, put another guy in the passenger seat and it rides like a Cadillac. The key for me was getting just enough torque to hold against so I didnt over correct. Mike

[kramr]

jcdogfish wrote: From my experiences with a BassCat, if it is set up properly, with a little guidance you should be fine in a few trips. If you are experienced you wont know it is there. I would suggest an inexperienced person drive the boat with the factory setup for a while, get comfortable with it before you start jacking around with engine heights and props etc.Exactly what I intend to do. Also, my wife is my fishing partner, everytime I even look at the motor she wants to know what Im doing.

[Gasbasser]

Well, I got some chine with my new Jag, usually at about 70.3 or so. Havent figured out how to deal with it, so I usually just trim down and cruise at 69. Its a work in progress and still breaking the engine in and not running WOT for more than 5 minutes. Its a little scary when that big ole Jag starts to dance.Britt

[kramr]

Mike,Like I said to JC, Ill stick with the factory setup until I get familiar with how the boat feels at speed. The cadillac ride is my goal.

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