High speed porpoising

[jamey1e]

What will cause a boat to porpoise at full throttle? The current setup is a 2019 ZX200 with 7 dot's showing and prop is a 23-T1. It also has one 10ft Talon. Any time I try to get near full trim the boat will porpoise. It's not bad but enough to make me think somethings not right. I generally run light and thought maybe I needed to move some weight off the bow but it didn't help any. Any help is appreciated.

[woppercatcher]

My 2018 ZX200 acted like this when running in somewhat rough water. I lowered it down to 6 dots and it helped.

[Fishysam]

If you over trim and have the motor to high. A different prop can change this from happening but you may loose speed just from that. I would trim a touch less or lower the motor to keep the prop biting

[ifishinxs]

Depending on how much weight your carrying and were it is placed can have an effect. If your porpoising you need to trim down until it stops. If I have 2 passengers in my boat I can’t trim out very far. It’s the nature of the beast.

[Squire]

porpoising is caused by not having enough lift. So you can shift weight back, lower the motor deeper in the water and use trim to create an angle with
more lift or try different props with more lift (Croison) including 4 or even 5 blade props. I had a skeeter fx21 that would porpoise and it was a pain. I lowered
the motor a bit and upgraded props, but it was never as good as I wanted it to be, so now I have different brand boat that allows me to carve lines. The new
skeeter fxr purportedly has some hull changes to reduce porpoising due to customer feedback.....

[jamey1e]

I appreciate it guys. As previously stated I tend to run light carrying just my gear and 99% of the time I fish alone with less than 1/2 tank of fuel. When it does porpoise I trim down but have to go way down to make is stop. I'm going to drop the engine to 6 dot's and see what it does. I'll post results this weekend.

[AllyFishing]

What's this "dot" stuff your referring to? Its a ZX200 so I'm thinking maybe a 19 footer?? You didn't mention the HP on the motor which is huge when it comes to performance.

The only way to set up a boat is to match the engine height with the size and HP of the rig. The less HP the lower the gearcase so it can carry the boat. The engine height is determined by measuring your prop to pad measurement and not by looking at dots on a JP (unless this manufacturer uses a standard JP for every hull and motor and the dots represent a specific prop to pad measurement). If for example a hull is heavy and maybe not powered by max HP that it's rated for then it may need to have the engine deeper because the power will not carry the bow. A good starting point is usually 3.5" prop shaft below pad of the hull.

These newer Skeeter are pretty darn sharp these days!! I like their looks and I hear they run pretty darn good too.

[jamey1e]

What's this "dot" stuff your referring to? Its a ZX200 so I'm thinking maybe a 19 footer?? You didn't mention the HP on the motor which is huge when it comes to performance.

The only way to set up a boat is to match the engine height with the size and HP of the rig. The less HP the lower the gearcase so it can carry the boat. The engine height is determined by measuring your prop to pad measurement and not by looking at dots on a JP (unless this manufacturer uses a standard JP for every hull and motor and the dots represent a specific prop to pad measurement). If for example a hull is heavy and maybe not powered by max HP that it's rated for then it may need to have the engine deeper because the power will not carry the bow. A good starting point is usually 3.5" prop shaft below pad of the hull.

These newer Skeeter are pretty darn sharp these days!! I like their looks and I hear they run pretty darn good too.

Umm...yeah, it's a 2019, ZX200. These are sold with 200 SHO's. I take it your not familiar with Skeeter boats? Particularly the ZX line which comes from the factory (unless upgraded) with slidemaster jackplates. They have dot's on top of the slide for quick reference to engine height.

[HoffaFXR20]

Not sure if you subscribe to the Yamaha Motors app. They have performance bulletins for all makes. I just looked at the bulletin for a ZX200 with a YF200LA which I assume is the motor on your ’19 ZX200.

yamaha has the engine mounting height at #3 dot on the jackplate.

The prop is VMAX series DIA:15.125 and Pitch 25.

[woppercatcher]

Not sure if you subscribe to the Yamaha Motors app. They have performance bulletins for all makes. I just looked at the bulletin for a ZX200 with a YF200LA which I assume is the motor on your ’19 ZX200.

yamaha has the engine mounting height at #3 dot on the jackplate.

The prop is VMAX series DIA:15.125 and Pitch 25.

The standard prop for this boat is the 15 7/8 23T2 not 25. My 2018 came from the factory mounted on the 3rd mounting hole from the top and at 7 dots. I had the same issue as the OP so I lowered to 6 dots which solved the problem for me. I lost a little WOT RPM. FYI, they changed the hull from older models along with the prop, mounting hole and also the motor was mounted to the plate with wedges. My brother has a 2011 and it runs way better than my 2018. It has the 25T1, wedges on the plate and the motor is mounted lower as well. I've heard but can't verify the reason for the different prop and mounting on later models was to increase the RPMs for some reason but I have no idea why.

[AllyFishing]

I am a little familiar with some Skeeter's as a few of my friends own ZX models. I do know they come with static slidemaster JP's but never heard any of them speak about dots on the JP.

So obviously the factory feels (as a result of their testing) every single ZXxxx with identical JP's and identical model Yamaha motor "should" be set at a specific prop to pad height from the factory? That prop to pad measurement is what those dots are representing. I would want to know those measurements. Not every rig regardless of the model and the HP will react the same once loaded by the owner.

It's like talking abut "tournament loaded" is a personal thing and not all are the same. Load distribution and prop will have cause and effects very different from owner to owner.