Just re powered my 1997 492vs ranger went from 225efi to 250 optmax.new motor runs great but has a pretty violent chine walk at WOT.I have owned this boat for 15 years and you could turn loose of the wheel while it was on the pad[though i never did].I can trim it down and it stii runs about 10mph faster than the 225 but it is not up on the pad . boat is loaded the same way as always and same 25 trophy prop.I have a 8in jackplate and used to be all out at about 1/2 on the trim guage now i can only get to about a 1/4 on the guage before it starts to chine walk.would this indicate the motor needs to go up or down.apreacate any help

Usually up, a trophy will ride a 1/2" higher then a Tempest.

If he's chine walking at 1/4 trim that motor needs to come down more than likely.

i agreee. motor needs to come down a bolt hole.

You need to measure your prop shaft in relation to the pad. From there we could help you more. It could be possible its too high. But i'd suspect you have other issues like holeshot problems.

Chine walk usally starts around 60 to 61 MPH.
The boat is obviously alot faster with the new motor so bow lift and trim angle will be different then what you are used to.
The setup will be different as well. You will have to drive the boat alittle more now with your newfound top end speed. Measure the motor and set it up correctly but it will still drive different so get used to that.

You guys are a wealth of knowlege,thanks for the imput.
Bryan you touched on the hole shot .I had the prop re-worked and it seems that it is right on the verge of blowing out.so I am going to try a 25 pitch fury and check the prop shaft to pad measurments.
Thanks to all

The verge of blowout on holeshot is usually what you want. There is now way anyone can really help you here unless they have the same combo. Need prop shaft measurement and RPMs and WOT to be able to help you with the right prop.

wealth of knowlege. call steve at steve custom prop.

It is possible that the motor needs to go up instead of down.

Yep. I would get a good measurement on propshaft height and go from there. I have seen chine walk more often caused by a motor being buried too deep than too high, but you need an accurate starting point first.

I had this kind of walk happen to me once.

You have to understand what the causes for chine walk are in the first place, Chine walk is a back-and-forth wobbling effect of the hull created when hydrodynamic forces try to balance the boat up on the primary pad and the supporting lifting strakes on each side of the pad. Each time a propeller blade enters the water and another exits, they are constantly trying to throw the boat off the pad. Now, if the prop is getting too much bite, it creates chine walking. This is typically results from improper rigging - not setting the motor at the right height.

And in the MAJORITY of cases its caused by the motor prop being too deep in relation to the hull bottom at (proper) running trim -- you are likely better off going UP - and re-cupping your prop to match new performance characteristics of the new motor --

I think you will see it a lot better with the Fury. A reworked Trophy will cause more bow lift. Had Gambler w/200EFI Merc w/ slight mods, that got wild with chime walk(almost dangerous) when I put a Trophy Plus 25pitch prop on it. It had been reworked also. Did better allaround with a re-worked 26 pitch Tempest.

Is "chine walking" and "chime walking" the same thing?

Yes its the same thing. And you need to go to a 26 pitch prop.

erniem - chine walk is pretty common on performance hulls like yours.

As the hull accelerates, lift increases and the wetted running surfaces that are required to support the hull are reduced (more Speed = more Lift = less Surface). As the speed increases throughout the velocity range, the hull often gets to a point where the lifting surfaces become very much reduced and the hull is now "balancing" on a small area of the vee-portion or the "vee-pad" of the hull. When that surface becomes sufficiently small, it becomes very tricky to "balance" the hull on its vee or pad. The result is a rocking of the hull from side-to-side. This rocking can tend to get a little more extreme with each motion, and so the "balancing" must then be provided by additional driver (steering/throttle/trim) input in order to maintain the hull in a balanced state.

With some driver input, the condition can be stabilized. With changes to hull setup and/or changes to the driving technique the condition can be alleviated.

Chine walking is predominantly characteristic of vee-hulls with deep Vees (more deadrise), hulls with deep or narrow running pads and hulls, with a Veed pad or no pad (straight vee). These bottom designs are just more inherently difficult to balance at higher speeds. Another contribution to chine walking can be seen at higher speeds from "propeller slap" (usually seen more with props of fewer blades). As the prop turns, each blade enters the water and another exits the water. This irregular in/out of every blade, changes the dynamic forces at the location of the propshaft, repeatedly putting an imbalance on a hull that is trying desperately to balance on it's vee or pad, and ultimately initiates chine walking.

Setup of your hull and driver "seat-time" are the best solutions to the problem. Usually an alteration to the hull, or hull setup and/or modification to your driving methods (read seat-time) will improve the problem.

Some established steps toward minimizing chine walking include:
1. Check & adjust steering
2. Use solid mounts
3. Clean Hull Lines
4. Weight balance of hull
5. Motor height
6. Propeller selection
7. Seat time (experience)
8. Minimize Trim Angle

Summary: Optimize Hull Setup and Driver "seat-time"!

here is an article on "chine walk" that may help.

I am in the process of adressing the motor height,steering slop,and prop.thank you for your help.

checked motor height and it 3in below lowest part of v ,is that about right.

Definately