2001 Honda 50HP 4 stroke correct prop

"We have a 2001 Honda 50 4 str

"We have a 2001 Honda 50 4 stroke on a 20 ft party boat. Runs great, nice and quiet. But when I give it more than half throttle it quickly approaches 7K RPM on the tach. I am concerned that I might have the wrong prop and don't want to harm the engine. Is there a prop spec for this engine?"

Most likely you have a spun pr

Most likely you have a spun prop. Needs to be replaced and/or repaired.

"If the party boat is a pontoo

"If the party boat is a pontoon boat, the prop will probably be somewhere between 9 to 11 pitch depending on the weight of the boat. Each motor/boat combination are unique and

I am with W D Neal, could be a spun prop. Try another prop, if you have one or borrow one if you can for the test.

If this boat is new to you, where are all the people sitting? If they are sitting to the front, their weight will cause the engine to sit higher in the water than it should and you could be cavitating. (Basically, the prop doesn't have enough water to grab)

Try moving the majority of people to the back to see if there is a change.

Also, on a pontoon boat, the motor generally should not be trimmed up. A straight vertical position or slightly off the full down postion works as well as any and keeps the motor in the water.

Again, if this is a new boat to you, the tachometer may not be set correctly. There have been some issues of tachometers not reading correctly on Honda 50's before 2005 unless there was a modification or a special tachometer was installed that came with each 50HP at that time."

Thanks for the advice guys. I

Thanks for the advice guys. It is a pontoon boat and motor is trimmed vertical so it isnt cavitating. Does the same thing if I have one or many people in the boat.

What is a "spun" prop and how do you recognize it? Is the prop loose on the bushing that drives it?

"There is a rubber hub pressed

"There is a rubber hub pressed inside the hub of the prop. If the prop hits something in the water, the hub takes the impact and breaks away from its hold inside the prop. After this happens, the prop will turn and propell the boat at slow speeds so you can get back to the dock. If you try to go faster, the grip will no longer hold and the prop will slip when the motor accelerates....thus the rpms go way up and the boat goes no faster.

Sometimes you can see damage to the prop and pieces of rubber around the hub.
The easiest test ia to change the prop with a known good one."