2000 90 lower unit questions

[Ron Clifton]

My 90 HP 2000 Yamaha spun the prop. I have repaired it. There is no outer sign of any damage. The boat is out of the water. With water muff turned on, the engine shifts into reverse and forward and the prop turns apparently correctly for each gear. With the engine turned off, as expected, the prop cannot be turned when the shift is in reverse. However, when the shift lever is in forward, the prop can be turned by hand in either direction, as if it is in neutral. There is a slight clicking sound when turning it. There is also a similar sound when turned by hand in neutral. Does this indicate that there would most likely be no forward thrust in the water and that there is probably damage to the clutch or shift leaver and a rebuild is required?

[madharchod]

most probably i would check if the cable control is engaging the gears is working properly and if it is then i will be looking at the gear case ,as you saying its making clicking sound in neutral gear this tells me that the engine is not fully in neutral as if it is in neutral there should be no sound either way ,and when you say in reverse you cant move it ,it shows the gear is engaged and in forward it moves one way means it is half engaged ,check the controls first to determine the problem
cheers

[Ron Clifton]

Thanks. I will check out again the cable link and shift rod. After I wrote up the problem I wiggled the shift rod around, ran the engine, shifted in and out of f/n/r and then re- checked w/ motor off and there is no clicking in neutral, but prop still does not engage in forward when prop is turned by hand.

Since the prop is engaged in forward with the engine running, might it be that the engine torque engages the gear fully and that I would have thrust and the boat would be under power if it was in the water?

[TownsendsFJR1300]

Thanks. I will check out again the cable link and shift rod. After I wrote up the problem I wiggled the shift rod around, ran the engine, shifted in and out of f/n/r and then re- checked w/ motor off and there is no clicking in neutral, but prop still does not engage in forward when prop is turned by hand.

Since the prop is engaged in forward with the engine running, might it be that the engine torque engages the gear fully and that I would have thrust and the boat would be under power if it was in the water?

The engine torque won't have anything to do with the shifting.

I have to agree with the second post and would be checking the linkages and getting the LU in Neutral( for certain), disconnect the control cable, get the control box definitly in neutral.

Then check to see if the shifter cable slides on easily. If it doesn't, adjust accordingly. It may be off just slightly alowing partial engagement.

Good luck..

[Ron Clifton]

Thanks, Scott. I will follow up on your suggestion. Does it sound like my lower unit might be ok? I hope I don't have to take it apart!

[TownsendsFJR1300]

Thanks, Scott. I will follow up on your suggestion. Does it sound like my lower unit might be ok? I hope I don't have to take it apart!

If you didn't have issues before, I would think nothing would have damaged the LU. Heres a link with a diagram, it'd help get an idea what's going on in there:

2000 90TJRY Yamaha Outboard LOWER CASING DRIVE 2 Diagram and Parts

Once all the adjustments are set correctly, we'll have to go from there. Hopefully its just an adjustment in the shifter.

BTW, make sure you are getting equal movement from the control box cables in forward and reverse. Not likley but possible, if a cable is hanging up, frayed, rusted and isn't moving fully it won't shift the lower unit fully.

[Ron Clifton]

Made sure lower unit was in neutral. Disconnected pins to cable and to shift lever. Turned lever by hand through f/n/r. Same results. Prop engaged in reverse, turned w/o click easily in neutral, turned clockwise w/ clicking in forward, but would not turn counter cw in forward.

Should I drop lower unit w shift in neutral and then reinstall unit making sure lever stays lined up for neutral? Otherwise what do you suggest I do next?

[TownsendsFJR1300]

When you state you "spun the prop", I'm assuming your talking about the rubber hub assembly, not ANY DAMAGE to the internals of the lower unit, IE prop shaft, etc and the original fix was simply the re-hub to the prop?

With that said:
The LU shifter wouldn't have changed position (as you didn't have it off for a water pump as with the other thread). I honestly don't know.

I've read of certain linkages (don't know about your engine) failing/bending, which may be your issue.

If no one else chimes in, PM Sequoiha or Rodbolt, (or any other senior mechanic here) they'd know where to go next..

[Ron Clifton]

I changed the prop hub. I think it was spun on a muddy/oyster bed bar and there is no outer sign of any damage. Examination of the shift lever top side and turning it by hand after disconnecting the linkage seems to work ok going to and from forward, neutral and reverse. There is a distinct click into reverse and back to neutral but a less distinct click into forward. In fact it feels more like it slides into gear- sort of like the old Chevy power glide that we used to call "slip and slide glide"!

I plan to drain the lower unit today to check for metal shavings and water. From everything I have read, heard and done, I am thinking the clutch dog might be the problem.

Thanks again for your help. Any other ides would be appreciated.