Hit A Sandbar Boat Won't Go Faster Than 10 mph Now

[Dadkubow]

So here are the details. Just bought a 2006 tracker Tahoe 195 deck boat with a 2006 Mercury 2 stroke 115 horsepower Outboard. We hit a sandbar at 20 miles an hour and tore up the prop. Could not see any other damage to the boat. Drained the lower unit and looked for water and Metal and none was found. Put on a new black diamond prop that matched the old prop. Now we have very little forward speed it looks like the prop is just cavitating we are making a huge wake. get high engine RPMs almost instantly but no speed. Prop goes in forward and reverse gears just fine.

There is no unusual vibration or noise coming from the motor or lower unit.

When the prop is in neutral it spins freely in both directions by hand and the prop shaft is not bent. When the prop is in forward gear I can spin the prop by hand clockwise with a clicking noise but cannot spin it counterclockwise. When the prop is in Reverse I cannot spin by hand in either direction.

Is it possible that I broke a shaft or gearr?

 

[jimmbo]

The ratcheting sound in forward is normal, and the limited movement in reverse is too. Did you replace the hub kit as well as the prop?

 

[tpenfield]

+1 on the hub kit . . .

If there was other damage, such as gears/shafts, you would really know about it.

 

[Dadkubow]

Replaced the hub kit with the new prop since we converted to the new Mercury flo torq. Even replaced the power sleeve twice to make sure it was seated properly. I am totally baffled by this one. I guess I should pull the lower unit and check for shaft and gear damage or break out another thousand and take it to the shop.. : (..

We throw a huge wake behind the boat, hit 5800 rpms almost immediately just no forward torque. I can lift the motor out of water and shoot a huge rooster like nothing is wrong. Just under load no speed like a spun hub.

Totally bummed!

 

[Dadkubow]

Replaced the hub with the new prop. Even replaced the power sleeve twice to make sure I seated it properly. I can bring the motor out of the water and shoot a huge rooster like nothing is wrong. When I put the throttle all the way forward we get instant 5800 rpms and no speed like spun hub.

Should I pull the lower unit and check for damage?

 

[ondarvr]

Post a pic of the two props.

 

[Dadkubow]

No Title

I had my son take the boat out today and he noticed the RPM's would jump up and down drastically but nothing changed in speed

 

[ondarvr]

What are the numbers off each prop, diameter and pitch?

 

[jimmbo]

Looks like the skeg is bent to port, is it twisted as well?

 

[Dadkubow]

Props are are both 13.75 x 15. The skeg lost about 1/2 inch and has a small bend. No twist. Going to put a skeg guard on.

 

[ondarvr]

The skeg guard won't help.

 

[Dadkubow]

Going to take some video of the boat on the water. Hopefully it can show what's wrong. Spoke to several mechanics in the area and they are stumped. Suggestions ranged from shaft alignment, motor height (is that possible without breaking the transom?), to the coupler in the power head. Any thoughts?

 

[UKMike]

Have you checked the engine mounts for breakages? A broken mount or 2 or even transom issues after a sand bank mount, you will get cavitation issues on both these issues.

Hope it's none of those for you but I would check the engine mounts.

 

[UKMike]

I should add that if your prop or props are running true then it can only be an issue with mounts or transom, or your tilt setup in my view but again I would guess it is a broken mount or 2 and unfortunately I really hope it's not that, I recently hit a gravel bank at low speed and it broke a lower mount and snapped my steering arm, which meant a total disassemble and rebuild, which I did myself!!!

 

[Dadkubow]

After talking to several mechanics in the area today they said the same thing so I will go out tomorrow and check them out. I feel so bad because my son just bought the boat.

 

[Dadkubow]

Here is the video of the motor. Checked motor mounts and there is a small amount of play. Nothing crazy bad.

http://www.thebridgekidsbixby.com/iboatvideo/index.html

 

[jimmbo]

We
Hen purchased the new prop, did you compare it to the old prop? Specifically the dia of the hub tube?

 

[Dadkubow]

Jimmbo everything seemed to match exactly. The only difference was the the hub. My old prop had a rubber hub and the new one has the flo torq. I am baffled. It looks correct.

 

[jimmbo]

The problem is either excessive venting of exhaust gases, or there is a problem with the flow torq. Was a different thrust washer needed for the flow torq?

Can you post a side shot of the prop on the outdrive?

 

[ondarvr]

I think he already posted a pic of the new prop, just not the old one to identify any differences. To me it looks almost like the pitch isn't the same, being far less on the new prop.