BASS BARN banner
1 - 11 of 11 Posts

·
Registered
Joined
·
219 Posts
Discussion Starter · #1 ·
I have a 1998 yamaha 9.9 long shaft outboard. When I removed the lower unit to replace the water pump, I cannot get the lower unit back onto the motor and have the forward/neutral/reverse lever work.

I dropped the lower unit in neutral. Disconnected the shift shaft (the nut remained on the lower casings shift rod) and replaced the water pump. The prop spins both clockwise and counterclockwise, at this point.

When reconnecting the shift shaft, in neutral, the lower unit will not go onto the 4 bolts that connect it to the motor. There is a 1/2-3/4 inch gap. I don't want to force it onto the motor.

If I put the motor into reverse, the lower unit will slide onto the 4 bolts. But the motor will not go into forward. The prop still spins clockwise and counterclockwise, even when in reverse.

Without the lower shift rod connected to the upper shift rod, the forward/neutral/reverse lever will move the upper shift rod up and down.

Did the lower shift rod disengage, disconnect (whatever the technical term is) from something in the lower casing? Or what could my problem be?

I don't mind trying to fix this problem, but I'm not afraid/ashamed to take the motor to a dealer to make the motor good, again.
 

·
Registered
Joined
·
11,868 Posts
The shift rods are not all the way seated into the coupler. Take a good look at the coupler you have and you will figure it out. I doubt the lower rod came loose from anything if all you did was a water pump.

This is how I do it on the tough ones. Do not follow these instructions unless you understand what I'm trying to explain:

I am not familiar with that motor, but i normally put the lever in forward (upper shift rod all the way down). Then I pull up on the lower shift rod (reverse). that way I can hook up the coupler first then raise the LU by hand working the shift lever back as it goes up. Don't force anything!
 

·
Registered
Joined
·
219 Posts
Discussion Starter · #3 ·
Thanks,

I understand what you are saying. I tried to pull up the shift rod on the lower casing, but I could not move it. I tried pushing it down, and could not move it. Maybe I need to pull harder??

I can connect the upper and lower shift rods, with the nut, and I can raise the LU into position, but when I bolt the LU onto the motor, the shifter will only allow 2 positions, neutral and reverse (or forward, I forget which one).

That's why I thought maybe the lower shift rod came out from its place in the lower unit.

Any thoughts on this??
 

·
Registered
Joined
·
11,868 Posts
I just took a quick look at the diagram and there are a few different styles on that year.

One style that matches your description has a threaded coupler and then a locknut on the lower shaft. Is this what you have? If it is, that lower locknut may have moved up the rod making the rod "too long". Make sense? You should really check the manual for an adjustment procedure.
 

·
Registered
Joined
·
219 Posts
Discussion Starter · #5 ·
Yes, mine has the locking nut and the coupler. The coupler is frozen on the lower shaft and won't turn on the lower shaft threads. It would seem that all I would have to do is tighten the upper shaft onto this frozen coupler and all should be correct. But is isn't.

Just thought of this. When I turn the frozen coupler that is on the lower shaft, the whole shaft spins in the lower unit. Could this be the problem?? Maybe the lower shift rod broke in the lower unit. When I unscrewed the coupler, maybe the torque of the wrench broke the lower rod in the lower unit??

If this is possible or even the problem, what do I do to fix it?? Or, maybe it's time to "punt" and take it to the repair shop.
 

·
Registered
Joined
·
11,868 Posts
I hope you had a wrench on the locknut when disconnecting the coupler. I do not know if that shaft should spin or not. It is connected to a cam at the bottom. Hopefully someone here knows. You should be able to move the lower rod up and down to feel Fwd/N/Rev. Spin the prop while trying. If you can't, take it to the shop. If you can, you should be ok.

Looks like the coupler should be threaded 10mm onto the lower rod, then the locknut is tightened. Is the locknut frozen about 10mm (1cm) down?
 

·
Registered
Joined
·
219 Posts
Discussion Starter · #7 ·
I got a bad feeling about this one. I don't remember if I had a wrench on the lock nut (I did the water pump last summer) when I loosened the coupler. The coupler is threaded onto the lower rod about 10cm.


The locknut is not frozen, the larger, coupler is frozen onto the lower shift rod.

I'll try to move the shift rod while spinning the prop, but I'm not sure I'm gonna get what I'm looking for.

Thanks for your help.
 

·
Registered
Joined
·
11,868 Posts
Edit: saw your new reply. Good luck!




That is backwards from the diagrams I am looking at. They have the locknut on the lower shaft, below the coupler when put back together. Either way, I'm guessing the locknut moved down on the shaft when you unscrewed the coupler. Now when screwed back together the shaft is adjusted too long (the locknut has to be backed off). Does this make sense? This is all a guess based on what you are saying, just so you have something to look at while waiting for more replies from someone with experience with that motor.. They will probably say to take it to a dealer. Just as long as you don't force anything, or make it worse, it doesn't hurt to try.
 

·
Registered
Joined
·
219 Posts
Discussion Starter · #10 ·
The locknut is below the coupler and they are both on the lower unit's threaded shaft. I can turn the locknut, but the coupler is not turning. If I can remember from last summer, when I put the wrench on the coupler to turn it, it was very tight. When I finally got leverage and turned the coupler, the lower shaft/coupler spun off of the upper shaft. Maybe that is why the lower shaft spins in the lower unit. I may have broken/snapped something on the lower unit's shaft.

There is a screw next to the boot on the lower shaft. If I remove the nut, it appears on Yamaha's diagrams that the lower shaft will come out.

If I try this, maybe I'll see something fatigued/broken. Guess I can't do any more damage that a good mechanic couldn't fix.
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top