Flotation Inside Jackplate

[97mirage]

I recall seeing photos posted by drag racers of added flotation (specifically an inflatable ball) installed inside the jackplate housing (between outside of transom and inside of plate).

Does anyone have any pictures of what they used and can anyone comment on effectiveness (i.e. quicker planing)?

Thanks for any help.

97mirage

[Whaaaaat]

Have 4 lightweight volleyball sized inflatable balls in mine, that reminds me they need replacing.

Yes helps float stern higher at rest.
Higher stern helps wash over when slowing.
Higher stern helps holeshot.
Higher stern is faster in no wake zones plus easier to see in front at idle.

I don't see a downside.

I think there called playground balls if I remember. Come in different sizes, get bigger than the space from transom to rear of plate so they stay tight when inflated. I used 4 so I could fill the space as much as possible. Put the inflators where you can access them. Put in mostly deflated then pump them tight.

[LakeFever]

Great idea!

[Forkin' Crazy]

I think my friend used an exercise ball of some sort.

[perfmarine1]

Maybe a smaller motor would be in order,not.

[David - WI]

A "skid planer" to keep the plate from scooping water makes sense; extra "floatation"... no so much. Even if the cavity was 12" x 12" x 12" and half submerged at rest... you'd only get about 25# of extra flotation when you add the weight of the balls (about the same as having 3 gallons less in the fuel tank).

[Whaaaaat]

The 4 balls in mine weigh less than half a pound. Probably less. About the weight of a frosty beverage. I might measure later but I'm sure total volume is more than your guesstimate depending on offset from transom and height of bracket. Also is where your adding the flotation that is important. Its aft of the transom, even if only 25lbs, is location makes a big deal. I saw my waterline at rest raise almost 2 inches in the stern when I added them. Leverage. Lift your 3 gallons of fuel off the ground by hand. Then lift it with the tip of a 2foot pry bar.

A couple inches really helps with a low stern boat and or a 15' mid. Keeps down the washover when coming off plane.

A skid planer or fin only works with forward movement. This is static lift, with a negligible weight penalty.

From a dead stop to a full plane its always going to be faster the closer you can start to you desired boat attitude.

Time to replace these. At least 1 is flat.
I put the pvc in there to keep the bolt heads and studs from popping the balls.

[DangerNewb]

I had two red "kick balls" on mine when I hard a seebold ski eagle. The location height of the balls in relation to the water level made it ineffective. Most of the balls were above rhe water line.

[David - WI]

The 4 balls in mine weigh less than half a pound. Probably less. About the weight of a frosty beverage. I might measure later but I'm sure total volume is more than your guesstimate depending on offset from transom and height of bracket. Also is where your adding the flotation that is important. Its aft of the transom, even if only 25lbs, is location makes a big deal. I saw my waterline at rest raise almost 2 inches in the stern when I added them. Leverage. Lift your 3 gallons of fuel off the ground by hand. Then lift it with the tip of a 2foot pry bar.

A couple inches really helps with a low stern boat and or a 15' mid. Keeps down the washover when coming off plane.

A skid planer or fin only works with forward movement. This is static lift, with a negligible weight penalty.

From a dead stop to a full plane its always going to be faster the closer you can start to you desired boat attitude.

Time to replace these. At least 1 is flat.
I put the pvc in there to keep the bolt heads and studs from popping the balls.

It's insignificant, even in a superlight boat... but if it makes you feel better, that's what matters.

[Whaaaaat]

Try it. Cheap and easy way to gain everything I already mentioned above. What do you have to lose? If it doesn't do what I claim then just give the balls away. I'm sure you've wasted $15 on worse things, I have. Just ordered 4 new balls for $15. It helps. If it didn't I wouldn't be replacing them , even for the measly $15 and 20 minutes it will take.

Also when I change out the balls I am going to swap the pvc for cut pool noodle to keep the ball from chaffing. Nobody likes chafed balls.

[altamate]

I have a CMC 10” hydraulic jackplate, after the first year of use I thought that the boat was rather slow out of the hole and not getting on plane well. Even when I would drop the motor down it did not seem much better.

I was experimenting one day trying to find the best trim height on the plate, so looking back at the motor while starting out in the fully lowered position I noticed a fair amount of water spraying up the inside of the jackplate onto the motor.

The jackplates lower motor motor mounting surface was sitting in the water while starting out and acting like a water brake. I trimmed away a bunch of the lower unused section of the surface and solved the problem.

[Whaaaaat]

I have a CMC 10” hydraulic jackplate, after the first year of use I thought that the boat was rather slow out of the hole and not getting on plane well. Even when I would drop the motor down it did not seem much better.

I was experimenting one day trying to find the best trim height on the plate, so looking back at the motor while starting out in the fully lowered position I noticed a fair amount of water spraying up the inside of the jackplate onto the motor.

The jackplates lower motor motor mounting surface was sitting in the water while starting out and acting like a water brake. I trimmed away a bunch of the lower unused section of the surface and solved the problem.

If you look at my crappy pictures above you can see on the bottom of my jack plate is a cover plate that keeps this from happening. Don't want to be dragging water when planning off.

[JBS]

Well here's my high-tech engineering. I have a stainless Marine bracket on my boat and a Jack plate. The motor sat back about 26 in, And set very low in the water. To solve that issue, I put two life jackets inside the bracket and remove the drain plug on the bracket. When the boat is sitting at rest the bracket fills up with water hence the flotation kicks in. I can stand on the transom and the boat does not move and I weigh 275. The boat planes off in a one boat length and then the water will drain out of the bracket

[Whaaaaat]

Well here's my high-tech engineering. I have a stainless Marine bracket on my boat and a Jack plate. The motor sat back about 26 in, And set very low in the water. To solve that issue, I put two life jackets inside the bracket and remove the drain plug on the bracket. When the boat is sitting at rest the bracket fills up with water hence the flotation kicks in. I can stand on the transom and the boat does not move and I weigh 275. The boat planes off in a one boat length and then the water will drain out of the bracket

Years ago I worked at a marina. Boat came in with a leaking bracket like that but for twins. They had filled it with about 200 water bottles to keep it floating until we could reseal it.

Why does yours take on water? Reseal it.