Learning to deal with Chine Walk.

[Reynard38]

Newby questions.
24’ Superboat Millennium CC. 300XS on a bracket. I gaining confidence runner her faster. Above 60 is when she’ll start to walk.
When it starts I bump the trim down switch a time or two seems to settle out. Then I slowly add some up trim.
Also should I experience much higher steering loads to port as opposed to starboard when it’s trimmed up, or should it be pretty even?

[rock]

As the prop spins it creates a paddle wheel effect that makes the boat want to turn right. That is the load you feel. When the chine walk starts put the boat into a slight left hand turn and see what happens.

Rock

[XstreamVking]

Bring it up to the speed just before the chine starts. Start with neutral trim. Very slowly raise the r's and play with the trim as you go. The goal is to stop the walk before it gets the boat unsettled. You have to control the boat all the way to top end. Driving thru the walk is not good lmo. Boat walks, slow dn and start creeping up again. Learn why the boat is unsettled. May have to work on balancing the hull better too by moving weight around. Torque in the steering needs to be addressed. It shows the lower is tracking with a "crab" angle which may also contribute to the chine walk. This is one reason I indicated to take it easy on the trim. jm2cts.

[Reynard38]

Thanks, makes sense and I’ll try it.
Next time out I’m going to take the GoPro and video the lower leg of the motor at speed. I’m also curious about the height it’s set at. I’m running a Torquemaster lower unit.

[Reynard38]

Bring it up to the speed just before the chine starts. Start with neutral trim. Very slowly raise the r's and play with the trim as you go. The goal is to stop the walk before it gets the boat unsettled. You have to control the boat all the way to top end. Driving thru the walk is not good lmo. Boat walks, slow dn and start creeping up again. Learn why the boat is unsettled. May have to work on balancing the hull better too by moving weight around. Torque in the steering needs to be addressed. It shows the lower is tracking with a "crab" angle which may also contribute to the chine walk. This is one reason I indicated to take it easy on the trim. jm2cts.

Thanks. What exactly is neutral trim and how do I know I’m at it?

[XstreamVking]

Just keep it safe and under control is the most important thing. And be patient. Lot of others will have info, as all of us have been thru the learning curve ourselves and have mastered it or found the cause of it if the boats not really drivable. edit.. Neutral trim is where the engine is fairly level in relation to the pad or keel. A 4' straight edge will give you the point where that is. Hold it against the bottom going to front of lower and observe where the cav plate is in relation to the bottom. They should be the same angle for neutral trim.

[Greg G]

What model prop are you running currently?

[Mark Poole ModVP]

Assuming that you have hydraulic steering....it has to be TIGHT, no play (squish). System has to be adequate and jam up tight on an outboard Vee. Also, high rake props are great for lifting but that paddle wheel effect is magnified. If everything is right, you just have to learn to drive it out.

[Reynard38]

Assuming that you have hydraulic steering....it has to be TIGHT, no play (squish). System has to be adequate and jam up tight on an outboard Vee. Also, high rake props are great for lifting but that paddle wheel effect is magnified. If everything is right, you just have to learn to drive it out.

I did purchase that bubble bleeder and throughly bled the system. That made a huge difference and it’s a big confidence builder feeling that connected to the boat. There was a lot of air in the system.

[Reynard38]

What model prop are you running currently?

I thought I had a picture of it, but I don’t. I’ll go down to the dock in a bit and take a look. It’s pouring rain here today.

[Reynard38]

Just keep it safe and under control is the most important thing. And be patient. Lot of others will have info, as all of us have been thru the learning curve ourselves and have mastered it or found the cause of it if the boats not really drivable. edit.. Neutral trim is where the engine is fairly level in relation to the pad or keel. A 4' straight edge will give you the point where that is. Hold it against the bottom going to front of lower and observe where the cav plate is in relation to the bottom. They should be the same angle for neutral trim.

I can do that with it on the lift from my smaller boat. Thanks again!

[CUDA]

Any torque tab on skeg?

[robert jordan]

I did purchase that bubble bleeder and throughly bled the system. That made a huge difference and it’s a big confidence builder feeling that connected to the boat. There was a lot of air in the system.
What is a bubble bleeder? Please tell me more about it or post a link to ware you purchased this.

[Reynard38]

What is a bubble bleeder? Please tell me more about it or post a link to ware you purchased this.

https://outboardst.com/product/bubble-purge-hydraulic-steering-bleed-and-purge-kit-ost-pbb-001/

[Reynard38]

What model prop are you running currently?


472790

472791

[Reynard38]

Any torque tab on skeg?


No

472792

[FUJIMO]

https://www.screamandfly.com/attachment.php?attachmentid=472792&d=1599433608

[fichrman2]

https://www.screamandfly.com/attachment.php?attachmentid=472792&d=1599433608

Certainly its the angle of the pic - or that skegs bent as hell

[LakeFever]

Practice and seat time and you get some muscle memory going on and it gets a lot easier.

[Li'l Toy]

Understand that this is not a situation where you learn to set up the boat and then you are done. You learn how to work the wheel to counter the chine walk, but you do that as long as you own the boat. Like Lake Fever said, it becomes muscle memory and you forget that you are doing it, but it is part of driving on the pad.

[LakeFever]

I’ve been boating my whole life and my first pad hull I wrestled with for a whole season, the second season I got the hang of it, the third season I bought my second pad hull with a lot more power and it started to click for me. Very little trim, and my mind is almost like a hair trigger response for getting out of the throttle and when I do trim up I’m wide eyed and ready for full tilt abort. Something like that level of intensity is how my mind is, but the seat time makes it more second nature and a lot more fun.

the chine walk doesn’t bother me much now but those hard to see sharp waves sure do. I try and pick my spots

[Greg G]

The Bravo you have has a lot of diameter. Couple that with no torque tab and possible slight air in the steering and all these items will add to chine walk. IMO find a shop who has a power purge machine and do that steering part first. Then, you might try a Rev 4 and compare it to the Bravo you are running currently. Then you can take on some next steps.

[XstreamVking]

4 blade should settle it down some and allow more positive trim too.

[vnemous]

What is a bubble bleeder? Please tell me more about it or post a link to ware you purchased this.
Im sure he means a Power Bleeder. Chine walk in a 24 Superboat kinda rare or am I the only one who thinks that?

[Reynard38]

Certainly its the angle of the pic - or that skegs bent as hell

I took a good look at it this morning and it appears to be straight.

[CUDA]

Im sure he means a Power Bleeder. Chine walk in a 24 Superboat kinda rare or am I the only one who thinks that?


If you been 98.6mph in a 21 Superboat you know set up well.:cheers:

[rgsauger]

I'm in the same boat...learning my shadow. I found these links helpful.

https://basscat.com/forum/groups/basscatowner/chine-walk-and-bow-torque/

http://www.bassboatcentral.com/new_page_2.htm

Play with your motor height, too. Too deep adds to poor handling.

Lastly...do NOT get out of the gas quickly when at speed!!!!! It's real easy to hook one by doing that. Trim down a few bumps to set the keel in the water and THEN get out of the gas.

[LakeFever]

Rgsauger thanks for that tip. I haven’t been fast enough yet to deal with major abort issues but I roll out of the throttle and trim down simultaneously. Nothing abrupt just instant reaction when it feels sketchy I get out of it and start again. Plus I run a v-king which tracks good on the deceleration.

Valero, two v-kings and a vandal which isn’t fast yet. Wanted this info here in case my advice doesn’t work for another hull I don’t want to steer anyone wrong. I’m still a newb and just lived this pad learning thing too is why I commented

[Reynard38]

I'm in the same boat...learning my shadow. I found these links helpful.

https://basscat.com/forum/groups/basscatowner/chine-walk-and-bow-torque/

http://www.bassboatcentral.com/new_page_2.htm

Play with your motor height, too. Too deep adds to poor handling.

Lastly...do NOT get out of the gas quickly when at speed!!!!! It's real easy to hook one by doing that. Trim down a few bumps to set the keel in the water and THEN get out of the gas.

Great articles, thanks.
And yes the previous owner gave me the same advice about reducing throttle slowly after bumping the trim down.

[rgsauger]

Great articles, thanks.
And yes the previous owner gave me the same advice about reducing throttle slowly after bumping the trim down.

So in my lack of experience, I hooked it three times over a couple of years and didn't know why. Started reading EVERYTHING on the topic and the consistent theme was getting out of the gas too quickly. Basically, the hull is up and out of the water on the pad and is slightly skewed from prop torque. So when I essentially chopped the throttle, it dropped the keel back into the water but at a slightly off-from-center angle and she hooked like a bittch to the left pretty hard. Now, bump bump on the down switch and then back out of it - not a prob.

Learning the pad...get just into the pad and hold it there and learn what she does and why she does it. You're never more than one or two bumps down from "stable" and safe. Have fun, wear you life jacket and kill switch, and don't get wet! lol

[Reynard38]

Shot this video coming back from coffee a few days ago. A lot of wakes, so I never opened it up, ut later in the video I did run it up to about 55mph.
Clamped the GoPro to the stern light. Next time I’ll get it closer to the engine.


https://youtu.be/1T3h3RP-gZI

[rgsauger]

As much setback as you have, I would be real curious about raising your motor up. What's your prop to pad measurement now?

[Greg G]

How much setback is that? Easy to experiment by raising the motor up one bolt height given the big diameter of that Bravo prop. Also, still would find a shop with a "power bleeder" if there is one close to you even though you have the hand held unit. Not expensive and checks off that important box.

[FUJIMO]

...nice video. boat runs nice too. yeah, if when you go even faster, and its chinewalking a bit, then its mostly cause of your generous setback. but that can be cured, as the boat seems to ride nice the rest of the time.

[vnemous]

That a crazy amount of setback for a 24 super.

[FUJIMO]

That a crazy amount of setback for a 24 super.
...yes...it is...narrow beam and all...

[Reynard38]

We had an overcast calmer morning yesterday. Was running 65 on the gps with no chine walk. Playing with the trim. Up a couple bumps, it’d start to wiggle a bit, one click down and it stopped.

I’ll get some measurements (pad to prop) as well as some pics to show the relationship of motor to hull.

Thanks everyone for all the help!

[rgsauger]

That is the PERFECT place to run while learning your boat. One click down and you are back safe. One click up and you start learning! Lol

[rgsauger]

Same stuff we are saying

https://www.screamandfly.com/showthread.php?134831-chine-walk-(help)

[WavetoWave]

Looks like you're running the Fleet Master. It appears low in the picture but you'd have to measure your propshaft to pad, you can raise it pretty high, which will help with handling, torque etc. But the Fleet doesn't have the torque tab like the TM. Once you dial in the height, like all the others said, just drive it, learn etc.

[Reynard38]

I got a suction cup mount for the GoPro so next time out I’ll get a close up of the engine leg at speed. The weather hasn’t been great here the last few days.

[Reynard38]

Was calm coming back from town the other day. Got it up to 72mph on the Garmin.
Was looking at the engine mount. Looks like I can go 1 hole higher.


https://youtu.be/93rk6HuMS_w

[Greg G]

Raise it up one for sure. Did you power purge the steering yet?

[Reynard38]

Raise it up one for sure. Did you power purge the steering yet?

Not yet. I did use the bleeder tool I have. Spent some time to get all the air out. Now when I try to move the motor by hand I get maybe 1/4” of movement whereas before it was well over an inch. Made a big difference in steering feel. Much more connected.

As to the height of the motor I can say that the cavitation plate is slightly above the aft lower edge of the bracket, which is well above the aft edge of the pad. Of course the pad is @ 2’ ahead of the back edge of the bracket.

[CUDA]

pictures

[bobby minis]

Do twin engine boats chine walk ?

[MDRURY]

Do twin engine boats chine walk ?

YES!!! They do if you can go fast enough for it.
Anyone can drive my LaveyCraft up till about 80mph. Above that, it has to be "driven".

Michael

[Reynard38]

Finally got that picture.

474188

[TooStroked]

Finally got that picture.

474188

I'd say you could bring the motor up quite a bit. Your prop shaft would be at about the right height - if you didn't have so much setback. Remember, the further you go back, the more you have to come up. To give you some perspective, here's the motor on my 22' Progression with 8" of setback.

https://hosting.photobucket.com/images/e60/tfwarda/IMG_1013_1_.JPG

[Reynard38]

I see what you mean, makes perfect sense.
The next time I’ve got her off the lift on the trailer I’ll raise the motor up a notch.

Thanks.

[JR IN JAX]

I can tilt the bow side to side on my Grandsport with just a small change [+/-] in the trim. Usually I will adjust my setup according to weight, fuel and passengers with engine height, trim and throttle until it is in the sweet spot. If I floor the throttle [90+], there is not a sweet spot unless I have a couple of passengers. In an Allison, too low a propshaft makes it hard not to wobble.

[TooStroked]

I see what you mean, makes perfect sense.
The next time I’ve got her off the lift on the trailer I’ll raise the motor up a notch.

Thanks.
You're welcome. Remember though that even set where I am - which is as high as I can go and still get out of the hole - I get chine walk above about 60 MPH. Between the Latham wing plate hydraulic steering and 25 years of seat time in the boat, it's a piece of cake to handle.

One other thought. You have a 4 blade prop which by definition will give you more lift. If you couple more lift with the motor being too deep, think of the effect as the motor trying to lift the stern. That'll force the bow down and more importantly, cause you to rock side to side at the stern. Yea, that's textbook chine walk - maybe on steroids in your case.

[Jimboat]

Chine Walking Article (https://www.screamandfly.com/content.php?150-A-Walk-On-The-Wild-Side-Chine-Walking-Why-It-Happens-and-How-To-Fix-It)