54" v boat can keep it on the water after around 63+mph

[jjrctech]

My 54" v Boat can't keep in on the water after around 63mph

I dont have video today but I gps it around 69.4+mph and the boat when flying up and landed and broke the Rudder.
Seem after around 57mph the boat become unstable

could it be the props 6017/3 to big?? (motor and esc have good temp 115f after 5 mins) or should i move the drive down or up??
running 29748Rpm

Below a link on a very old video but it only at around 75% power there.
Thanks

[Steven Vaccaro]

At around the 50 second mark the boat looks like the nose wants to come up. Did you try moving the packs forward? Or a strut adjustment?

[Fluid]

The video isn't real helpful if it isn't close to the current speed. There could be several reasons why the boat flew off the water, but we need to know a lot more information.

- What setup: motor, ESC, packs.
- A photo of the transom showing the strut depth.
- CG location now.
- Weight of boat RTR.

There could be a number of reasons for the boat to blow off, including strut depth or angle, CG location, trim tabs, total RTR weight or the overall design of the hull. Some hulls simply will not stay on the water above a certain speed.


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[jjrctech]

From the time of this video the drive were move down 2mm at the end points. Battery are about 22 in from the rear. Boat run about only about 12in from the rear or less in the water. its not running wet. I should of add the video but the person take did not click record.

weight of the boat is 25-27lbs Motor 1340Kv run on 6s, would smaller props and more Rpm make it more stable or its something esle??

[Brushless55]

do you know where your CG is at?
and what hulll is this?
you could simply be at its limits

[jjrctech]

do you know where your CG is at?
and what hulll is this?
you could simply be at its limits

The hull is a 54" bonzi fountain hull CG would be I think at 20-24% from rear if that is correct.

[Brushless55]

maybe moving the CG to 29-30%
but this hull I think is at it's limits??
Fluid will be able to answer for sure

[Fluid]

I'll ask again:

- What motor are you running?
- Where is the CG - exactly, not a range of 4%.
- What ESC are you running?
- What packs are you running - exactly (mAH, C rating, xP), not just the voltage.

We can't help you if you don't give us the information we ask for.

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[jjrctech]

I'll ask again:

- What motor are you running?
- Where is the CG - exactly, not a range of 4%.
- What ESC are you running?
- What packs are you running - exactly (mAH, C rating, xP), not just the voltage.

We can't help you if you don't give us the information we ask for.

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2 x Leopard 5692 1340kv, Swordfish 240 HV , battery 5000mah 6s hyperion 45C Constant and 90C Burst Where is the CG - exactly 22%

[jjrctech]

IMG_4367.jpg

This is the best picture of the boat at amost full speed 85-90% power boat.

[Fluid]

The CG is too far back, it should be between 27% to 30%, particularly if the boat wants to blow off.

You didn't mention it was a twin - were we supposed to guess? If this boat has twin props it may require slightly different strut settings than a single drive does. The twins props will not keep the transom up (and bow down) as well as a single does since they run shallower relative to the keel. That's not necessarily a bad thing, just different.

Telling us how far back the props are from the transom will help us too. A photo of the transom would have saved us a lot of wasted time trying to find out about your boat. Keeping basic information about your model away from those you expect to help you is not that productive. Not trying to be a jerk but we can't help you if we do not know all about your boat. Getting that information from you has been like pulling teeth. Move the CG forward and see how the boat runs.



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