115 2T shifting problem

[axolotl98]

Hello guys.
Its an old lady, model 1994, but I love her so much and I take really good care of her...
Just 3 years back, and after rodbolts suggestion, I have bought and installed a new SEI lower drive which has proven a wise thing to do.

Now to the issue at hand.

I am pressing the control lever downwards, and the engine revs up but reverse gear is not selected.
I have already replaced the plastic end of the shift control cable and adjusted it.
This seems to have worked for a few hours of operation, and the again the same problem pops up.
One thing I noticed is that I need to almost completely unscrew the plastic end on the control cable to make it work...Does this mean something?

Any simple ideas on what other thing to look at, adjust or replace before I end up at the local mechanic?

Thanks for your support

[TownsendsFJR1300]

Is the shifter end of the cable moving at the engine when shifted to reverse?

Can you manually, (with the shifter cable disconnected at the engine)-engine running on muffs/water shift into reverse using you hand at the linkage?

Lastly, when you re-assembled, did you confirm BOTH the control shifter at the helm was in NEUTRAL AND, the lower UNIT was in NEUTRAL? If you were off a spline, I would think that may cause your issues...

[axolotl98]

Is the shifter end of the cable moving at the engine when shifted to reverse?

Yes

Can you manually, (with the shifter cable disconnected at the engine)-engine running on muffs/water shift into reverse using you hand at the linkage?

Absolutely yes. Both forward and reverse can be easily selected by hand, as well as for just a few hours after I connect and adjust the shifter cable end..

Lastly, when you re-assembled, did you confirm BOTH the control shifter at the helm was in NEUTRAL AND, the lower UNIT was in NEUTRAL? If you were off a spline, I would think that may cause your issues...

Again yes. As mentioned shifting works without an issue for just a few hours and then it just denies going into reverse...Funny, really funny problem...

[Sequoiha]

Could you have a spun hub in the prop, gear cases are either in gear or not, either broke or not, if it works good for a while then starts acting up check the prop.

[axolotl98]

The shifting issue occurs only with the reverse drive. And thanks for the suggestion, but the propeller is fine.
Does anyone know whether there is any adjustable mechanism within the control box? Any plastic parts on the shifter cable that can bend or that need replacement there, just as in the engine end?

[TownsendsFJR1300]

The cables obviously are replaceable in the control box.

IDK what the ends are made of however, I think looking into the box (shouldn't be a big deal) would be a good step to rule it in or out...

Wether something broke in there, came loose, etc. Its shifting at the engine, the only other end is in the box or a jambing/rusty control cable..

[boscoe99]

First thing that I would do is to try and isolate the problem to either the motor or the throttle/shift box.

Disconnect the shift cable at the motor. With the motor running at idle use your hand to move the shift mechanism into reverse, back to neutral, then to forward and then back to neutral. Does it shift correctly this way?

If not, there is something wrong with the shift mechanism or the lower unit.

When was the last time the shift mechanism was greased? Should not have been more than a year ago.

If the lower unit shifts correctly by hand, but not when the control cable is connected to it, then something is amiss with the control box and/or shift cable.

With the shift cable disconnected does the shift cable move freely back and forth when you move the throttle/shift handle?

Oh, also make sure that the attach mechanism that holds the shift cable in place is in good working order. If the cable is not held firmly in place then shifting problems will occur. As an example, the F150 has a known issue where the attach mechanism pops out of place and inhibits the shift function. Not your model but stuff like this can happen on most any model.

[axolotl98]

As the lower unit seems to be shifting ok by hand, then the problem must be in the cables and/or the control box. I will be changing both control cables, since they are already in service for more than 5 years now, and check the internals of the control box. Thanks for your help guys !

[rodbolt17]

also inspect the shift rod ,you can see it where it exits the steeing tube and enters the lower casing.
if its hour glassed with rust it may be twisting.
older yamahas used steel shafts that rusted away occasionally.

[99yam40]

If that is the problem, I have seen on line someone makes a 2 piece shift shaft so you may not have to remove the power head to change it

[axolotl98]

Thanks for your input guys. Can you direct me to a link for this two-piece shift-shaft? That sounds like a very interesting idea

[99yam40]

Is your shift shaft the problem?
I will look for a link

A quick web search found it http://shiftshaft.com/