How To Detect Spun Prop Hub On Boat? (Explained)

The Prop or propeller hubs are responsible for protecting the outboard and boat’s lower unit gears from external impact.

But a spun prop hub will fail to protect your lower-unit gears, that is why you need to keep an eye to detect when your prop or propeller hub turns bad or broken.

Today’s article will guide you to learn the symptoms to detect a spun prop so that you can fix or replace it before your boat’s lower unit encounter further damages:

What Sign You Should Look For To detect Spun Prop Hub On Boat?

In general, one can easily identify a spun prop hub by inspecting the rubber hub’s physical condition, but some obvious symptoms help detect the issue even without a physical inspection.

The initial sign of having a spun propeller is when you notice getting your boat on the plane is taking longer than usual, and the hub is constantly slipping while you try to plane your boat.

What Are The Symptoms Of Spun Prop Hub On Boat?

Symptoms of spun prop or propeller hub on the boat or outboard motor are usually associated with the following explained indications:

1. Prop Hub Slips & Does Not Plane The Boat:

A damaged propeller or spun prop hub mainly delays the boat getting on the plane. When the prop hub becomes spun insider the propeller, the propeller starts spinning freely and will not harmonize with the prop hub.

Since the propeller and the prop hub do not coordinate during spins, the prop hub starts slipping, and you will visibly see the struggle to get on your boat on the plane.

2. Reduction Of speed & Power At High RPM:

Along with the slipping and delaying, another initial indication that your prop hub turned spun is when you see the speed is reducing at high RPM and also the power is reducing with excessive RPM.

If you observe closely, you will notice that the engine revs with little or no acceleration.

But the good news is, it will still allow you to move your boat towards the nearest landside if you use the slower RPM.

3. Poor Performance, Fuel Economy, Acceleration & Noticeable Vibration:

If you notice the propeller fails to keep your engine in the accurate RPM range, which is also resulting in poor performance and fuel economy on your boat. That is a clear hint that something is wrong with your internal prop hub, and you need to fix it.

You may also experience that your boat is not responding well during acceleration and corner movements. Some consumers also claim that when the prop hub spun, they heard a slightly noticeable vibrating sound.

These are the symptoms that will let you know when to do a thorough inspection or investigation at the inside prop hub of your boat’s propeller.

How Should You React If You Detect Spun Prop Hub On Boat?

Whenever you encounter or notice any of the symptoms that I have mentioned and explained earlier, make sure to follow the below mentioned easy steps to fix your problem:

Determining The Damage Level:

Before you decide on purchasing a new prop hub to replace the existing one, make sure it is needed.

To confirm the replacement need, take off the prop and inspect for burnt or frayed rubber in it.

Now, take a permanent marker and draw a line on the inside end, over the inner and outer side. After that, securely set the prop back again, and run the propeller for 2 to 3 minutes at high RPM.

Then turn off the motor and look at the drawn line. If you see the line is not matching, you will need to replace the hub.

Investigate The Propeller Bore Thoroughly:

Now, you need to investigate the propeller bore to see if there any cracks or visible damages.

If the propeller bore is out of round, instead of replacing the prop hub, you have to replace the propeller.

Take The Accurate Measurement, Specs, Tools To Remove Older One:

Now, if you are determined about the replacement, either you can do the job entirely by yourself or hire an expert or professional to do that.

If you want to do the task, first measure the hub bore to find out the accurate insertion funnel to use. Then, you need to set the propeller on the determined correct funnel and use the matching hub driver to push your existing prop hub.

You need to push the old one out through the propeller into the funnel to remove it.

Replacing The Older Prop Hub With The New One:

Before putting the new one in place, make sure the ram is flat and square with the press table. Otherwise, while pressing the new prop hub on the press table, the hubs will go into the off-center.

Now use proper support under the propeller, and coat the insertion funnel and hub driver with the lubricant.

After lubricating them, press into the propeller and see whether you can twist the insertion funnel freely or the funnel stuck in there. If you can rotate it freely, that means the new prop hub installation is done successfully.

Is Replacing Spun Prop Hub On Boat Typically Expensive?

Technically speaking, replacing or repairing a spun prop hub cost is a cheaper and economical range.

But it can still vary depending on your boat motor type or model and where you will do the replacement.

It is a five to ten minutes task, only if you know how to do it correctly.

A typical aluminum prop hub replacement may cost $100 to $150 and the cheaper ones are also available at $50 to $100 pricing. But if you are planning to buy a steel-made one, it may cost around 400 to 700 dollars

How Often Should You Check Or Service Prop Hub On Boat?

In general, a new prop hub lasts until the internal coating comes off or you hit something with high force and damage the rubber hub located inside the propeller.

You mainly need to check the prop hub whenever you notice any sign of damage in there. But if you are an aggressive or regular boater, you should do the regular servicing as well, to avoid any potential damage.

You should inspect the prop hub after every 4000 hours of operation to prevent any problem beforehand.

Final Thoughts

Though spun prop hub may seem an easy problem to solve and fix, it can be an initial indication of further big issues such as water pump impeller failure, clogged cooling system, or even the outboard engine failure.

Therefore, keep a close and careful eye on to detect the symptoms before the spun prop hub leads the damage furthermore extreme commotion.

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