OMC 140 - Stringer 400 - Problem on water

[technochris]

:facepalm:
Last weekend I had an issue with the Out drive of my boat. Heading upstream at about 25 mph, the out drive lost power and the engine revved up about 1000 rpm. I was able to travel at about 7.5 mph to the dock.

I have the drive apart and replaced a worn impeller, even though it was still in one piece, I don't think the impeller caused the loss of power. What can I check while I have the upper and lower separated? if I manually shift the Lower housing into gear (forward or reverse) and spin the drive shaft, it rotates smoothly. With the Upper off, that spins smoothly also. All Spline shafts looked great with little to no wear. I cannot remove the lower units bearing carrier to get to the clutch dog to check the gears, But it feels smooth anyway.

Anyone have an idea were to look next?

 

[southkogs]

I dunno' the 400s very well, but just for makin' sure: is your prop hub, pins, etc. all okay?

Welcome aboard.

 

[technochris]

the prop and prop shaft are in great condition. Can the Prop spin around its rubber core?

 

[technochris]

southkogs. what Pins?

 

[Grub54891]

the prop and prop shaft are in great condition. Can the Prop spin around its rubber core?

Yes it can. Mark the inner hub out to the outer prop,with a sharpie,or scribe it. Take it for a run,till it revs up,check the line,if it moved you will see it.

 

[Scott Danforth]

with your stringer, the things that could have happened in probability are as follows:

1. upper/lower driveshaft spline failure (the splines at the raw water pump)
2. hub failure
3. ball gear failure
4. coupling failure

since I have experienced 1, 2, and 3, and have never seen 4, my first suspicion is #1

 

[southkogs]

No Title

southkogs. what Pins?

Sorry Chris - yours is a little different than mine, you've got the castle nut with one pin: #94 below:

with your stringer, the things that could have happened in probability are as follows:

1. upper/lower driveshaft spline failure (the splines at the raw water pump)
2. hub failure
3. ball gear failure
4. coupling failure

since I have experienced 1, 2, and 3, and have never seen 4, my first suspicion is #1

I was kinda' going through Scott's list, and think you mentioned you had already looked at the driveshaft spline. So, I started thinking prop hub - mainly 'cuz it's kinda' nice if it's easy and relatively cheap like that.

Grub's got a good way for you to test your hub in post #5.

 

[superbenk]

Agreed with the prop comments. I'd expect a whole bunch of weird noises if it were splines or ball gears & id be surprised if you'd be able to maintain 7.5mph with those failures.

 

[Scott Danforth]

I was able to continue on at idle after I stripped out the shaft splines to get me back to the dock.