Hit a short log with my outboard

[hatboat]

Went for a boat ride WOT and all of sudden the boat started to lose speed. I immediately put the boat into neutral and took a look at the motor. In the front of the shaft was a 2 foot log stuck to the shaft. I removed the log and it started up right away. When I put it in gear, it sputtered and stalled. Tried it four times and final it opened up again although it seemed like it didn't get to top speed. What are the possible problems with hitting a log, dragging it and losing speed. Again, it was just a 2 foot log. Any thoughts? thanks

 

[littlerayray]

Spun hub or messed up prop

 

[hatboat]

When in neutral, the prop spins freely when I move it by hand. Also, when I go straight forward, it opens up, when I turn it slows down and sounds like its going to stop until I straighten up again. Can I fix the prop or do I need a new one?

 

[jrs_diesel]

Yep, if the prop took a hit, a spun hub is likely. Check the blades carefully for any dings, dents, chips, and bends. A prop shop will be able to fix up your prop if damaged and re-hubbed.

I'd look over your gear case too and make sure it isn't damaged either. You didn't mention how hard the hit was.

 

[hatboat]

Thanks. The hit wasn't hard at all....didn't notice it. When we slowed down of course, I knew to throw it into neutral. What would cause it to slow down when turning but work fine when going straight...are you thinking the gear case? If so, how do I check my gear case? Thanks again.

 

[jrs_diesel]

If you can shift into forward and reverse with no problems, then I bet your gear case is fine. You can also pull the prop and check the prop shaft for straightness.

It really sounds like you have a spun hub. If you are not aware, the hub is simply a piece of rubber in between the prop and prop shaft. It has two jobs. 1st is to transmit the engines force from the prop shaft to the propeller in order to move the boat. 2nd is to cushion impacts to protect the gear case and engine from shock damage. If the hub gets over torqued (like in an impact) the hub spins freely inside the prop. Once it breaks loose, it's ruined. But, it will usually have enough grip in order to spin the prop at low speed in order to get you home, but won't be able to handle high power, as you found out in your turns. Having a prop re-hubbed is a lot cheaper than fixing a wrecked gear case.

 

[hatboat]

Thanks for that. I put a mark on the inside and outside of the hub and took it for a test run. When I got back to the dock, the lines were still lined up so it's not a spun prop. Before hitting the small log, I replaced the diaphragm on the fuel pump. Could I have installed it improperly? When it's WOT it cuts in and out like there is no fuel getting through, it's only subtle but never dies or loses speed (at least not that much). Is this a fuel related issue due to my working on the fuel pump or could the hit log done something to cause that. Appreciate all the help.

 

[jrs_diesel]

Does the engine rev up when your problem happens or does is seem to lug and die out?

If it's stalling out, pump the primer bulb or hit the choke and see if it picks up.

 

[hatboat]

It's not really stalling out...it's more of an in and out sound, hard to explain. But it never feels like it's going to lose power. I don't have a tach so I'm looking at the speedometer when it happens and it loses a couple mph but then goes back up. It starts up right away, idles fine, planes perfectly, but with WOT it does that in and out.

 

[GA_Boater]

When in neutral, the prop spins freely when I move it by hand. Also, when I go straight forward, it opens up, when I turn it slows down and sounds like its going to stop until I straighten up again. Can I fix the prop or do I need a new one?

Is the motor slowing down or is the boat speed is dropping off during a turn?

 

[hatboat]

It does slow down on turns and it does the in and out sound when going straight, but definitely a decline in speed on turns.

 

[GA_Boater]

It does slow down on turns and it does the in and out sound when going straight, but definitely a decline in speed on turns.

Is the motor speeding up or keeping the same RPM when the boat speed drops? What is the in and out sound?

 

[hatboat]

My Tach isn't working but the speedometer shows a drop of about 2-3 miles and then comes back up. The in and out sound describes the sound of the motor when it drops and then goes back up. It's not a loud rev up and down and my assumption is that there is not a drastic drop or increase in RPMs.

 

[GA_Boater]

It sounds to me like the prop is cavitating listening to your words. Do you have power trim?

 

[hatboat]

No power trim unfortunately. I don't think the log hit the prop, however when I stopped, lifted the motor the log was stuck to the shaft, it came off easy. If the prop is cavitating, does that mean a new prop or something worse?

 

[jrs_diesel]

Stuck to what shaft?

 

[GA_Boater]

Stuck to what shaft?

I think he's saying the log was t-boned by the snout of the lower unit.

 

[GA_Boater]

No power trim unfortunately. I don't think the log hit the prop, however when I stopped, lifted the motor the log was stuck to the shaft, it came off easy. If the prop is cavitating, does that mean a new prop or something worse?

It means play with your trim pin until it stops cavitating, if that's what it's doing and if nothing in the swivel or motor mount didn't get bent or broken.

What motor do you have?

 

[hatboat]

Ah ok, makes sense. It's a Johnson Outboard 70 hp. I just got back from taking it out. It did the same for the first 15 minutes. I put it neutral and started it up again and it seems to have stopped doing it. However, that might not happen when I try it cold again. Is it possible that it worked its issue out on its own or is that more wishful thinking?

 

[williamfw57]

I hit a long log and the same thing happened ,,,damn small world