2017 Nitro Z18 wobble

[Pski's Angling Adventures]

Only had the boat about 6 weeks now and only have about 6 hours on the motor. 175 Pro XS on a 8 inch Slidemaster jackplate. When running near full trim and about 55 mph, I start getting a "wobble" on the bow. The bow starts walking left to right and back again. If I dont come out of the gas and or trim down it progressivly gets worse. I found that I have about .100 of an inch difference from side to side of the jackplate measured from the top metal trim strip going across the transom to the top of the jackplate. BPS claims this is within their tolerance though I dont see how that can be. My concern is that perhaps the motor is mounted on an angle. Anyone else ever heard of this?

[Bruce2]

My boat does that and they say it's a form of chine walking, my boat will do it even in turns at 56 mph, slight pressure to the left will help to control it....you can also try to raise or lower your motor also a little bit.

[mdtritn21]

It's chine walk and either get some one who knows how to drive the boat show you how for an hour or put in the seat time to learn to drive it by yourself. It could be that your motor is mounted too low prop to pad so measure it and get back with the measurement. This will show you how to measure it. http://www.bbcboards.net/showthread.php?t=62660

[Midnight Rider]

It's just chine walk. It can be helped a bit if the motor is raised, but you need to know where it is to begin with before you start changing things. So measure prop to pad as mdtritn suggested.

Is this your first "performance" hull? 99% of boats with a pad hull are going to chine walk at some speed, usually WOT and trimmed up for maximum speed. You have two choices: keep it trimmed down enough so that it won't do it, or learn to drive the hull to get the maximum speed out of the boat. Even a Nitro should do 60+ with the 175 XS Pro on it, IF it's setup correctly.

Do some reading about boat setup and chine walking to understand the physics involved, then go out and get some seat time and learn what to do to prevent it. You have to make corrections BEFORE it starts walking. If it's walking already, you're behind the curve. Just trim it down and start over bumping the trim a little at a time. NEVER chop the throttle when the boat is chine walking unless you enjoy getting thrown out of the boat quickly...trim down first, then come off the throttle if you want to.

[Bruce2]

I can raise my motor way up I still get the ass wiggle...been as high as 2 1/2 inch prop to pad and I'm down to 4 1/4 ptp now and still have it...lol

[Pski's Angling Adventures]

I've driven boats that chine walk and this feels different. Does anyone believe that jackplate being mounted crooked has anything to do with this?

[Rip Bass]

Motor being crooked doesn't matter,especially that small amount. A buddy had a 1997 Skeeter ZX 200 that was off a little over 1/4", measuring from top of transome to jackplate. You could visually see that the engine was crooked.It never made a bit of difference. The boat drove well and ran very well. Check your steering to see if you have any loose play,if not,then its most likely chine walk.

[rchavis]

Seat time and make sure the boat is load evenly or Balance .

[Bruce2]

Im glad im not the only one with this type of chine walk.....lol....mine will even do it thru turns at 55 mph...lol

[d'Wayne]

Simply overtrimmed?

[pmgoffjr]

It could be caused by a number of things, some might be obvious, some not so much. It's usually the prop losing it's clean water for an instant, and you're feeling it catching air, then when it grabs again the torque does funny stuff, so:
Make sure you don't have any junk hanging off the transom, transducer is a big culprit.
Hooked or rocker pad can cause it also, so lay a straight edge on your pad at least 4' from transom, it should be flat.
Crooked motor could cause it for sure, you can arc your transom to check square to pad, sometimes the motor is square to the pad, but the transom might look off.

[mdtritn21]

I don't think a .100 of inch measured from the metal trim on his boat shows the motor out of square with the pad

[pmgoffjr]

I agree, at least mark your transom mold marks, and see if your plate is square to those. What the top looks like is not important, only that motor is square to the pad.

[Bruce2]

Make sure your steering is tight also, no slop in cable it cabled steering.... i have done a bunch of stuff trying to stop mine from doing it to no avail and i have had people look at boat and can't find anything wrong with it...i have had 3 different props on it and it does it with every prop...old style trophy with double cup added....23m and im running a 25m now...even talked to Mark Croxton about it and he said he has never seen a boat do that before(i provided him a video)....

I'm not trying to hijack your thread im just telling you of my experiences with this wobble thing... only other thing for me to try is to drop motor on jackplate one hole and drop motor deeper to like 4 1/2 prop to pad...

[pmgoffjr]

I've had a couple that would get loose in the back. It's not chine walk and you don't drive to prevent it. It's random and you think you've blown out a prop the first time it happens.

Last one that did it I got the steering tight and had some cup added to the m prop I was running and that took care of it. Your fix might vary.

[Bruce2]

I've had a couple that would get loose in the back. It's not chine walk and you don't drive to prevent it. It's random and you think you've blown out a prop the first time it happens.

Last one that did it I got the steering tight and had some cup added to the m prop I was running and that took care of it. Your fix might vary.

That's what it feels like on mine..steering is tight even went with solid motor mounts...Thanks Pat...

[Pski's Angling Adventures]

The Nitro has hydraulic steering and appears tight. Prop is 2.5" below pad and running a 24 Fury prop. Only getting 5500 RPM so still have another 500 R's to go yet on my last 1/4" raise of the plate, water pressure fell from about 15 to 12 so thinking I probably shouldn't go any higher on jackplate.

[mdtritn21]

Before you do anything else drop that motor down 1/2" to 3" under maybe even 3 1/4" under because your too high prop to pad for a fury prop to run right and the stern is what's kicking out from the prop being mounted too high. You've got 21% slip showing at 5500 rpm's another sign of the prop being mounted too high so drop it down or go find a 24" tempest to run on that 175.

[sjengie11]

Don't know if this helps but my Skeeter does this at about 3/4s trim and 65-70 mph once you go faster it goes away though.

[Silkstringz]

Just fyi, your max rpm is 5750 on that motor. Not 6000.