1976 Johnson 25hp Jumping out of Gear

[juderopp40]

Bought tiller motor for cheap, bad dog and forward gear from the jump so I just bought a rebuilt lower off EBay. Ran it some with new lower and it did fine for about 2 hours. Then started jumping out of gear again?? Pulled it out immediately and pulled oil, had a little water in it but not much and no bits of metal…took it in to get resealed. Guy said the dog and gears looked great (got picture). Bout a month later I finally got the lower on and took her out. Immediately jumped out of gear again?? Was out for about 45 mins and only got one pull where I was able to get on plane without popping out. After that I lost forward gear, drove home in reverse.

Is there anything else that can be causing this? Couple things I will mention, the shift lefter seems to not go all the way forward and lock where it should in forward position, as if when I was getting it in forward it was “barely in there.” When I say I “lost forward gear,” this was not the grinding sensation that I knew to be the obvious worn dog and gear from the original lower unit, it’s like the “click” for the forward position for the lever is just out of reach, but like if I disconnect and moved the lower shift rod manually, it would still distinctly snap into place like it should. Is there anything I can adjust on the shift rod or at the connector/linkage where the upper and lower shift rods meet to correct the stroke of the shift lever in relation to the engagement of the clutch dog?
Please give me your honest evaluations of the situation, and let me know if you need more details. I will be grateful for any advice you might have as I’d love to keep this beautiful pre-emissions beast alive without burning up the E- fund lol.
(attached is picture of gears and dog from mechanic)

 

[Bailey Boat]

Sounds like a linkage adjustment may be in order......

 

[juderopp40]

Sounds like a linkage adjustment may be in order......

Thanks! I was thinking that was the case…Would anyone have good advice on how to do this accurately? Can’t find any good videos on YouTube, or people documenting this same situation with the year and HP that I’ve got.

 

[lckstckn2smknbrls]

Get yourself a factory manual if you can't find one there are some aftermarket ones.

 

[Pappy]

First off, it is not being held in gear by the dogs on the fwd and pinion gear. They are straight cut and therefore were never designed to hold themselves in gear. That is the job of the linkage detents and adjustments. Do NOT run it again until you have adjusted the linkage. Yes....there are adjustments!
At the base of the shift handle on the stbd side of the powerhead you will find a screw/nut that goes through a bell crank with a curved slot in it. This is your point of adjustment. In order to adjust you have to loosen the clamp screw on the handle itself. Once loosened you can now make the adjustment.
Since you have to pull the clutch dog further into forward gear the shift handle will have to be moved aft toward reverse gear a little bit. Do this and re-tighten the bell crank screw. Without the engine running get a good feel of how the prop feels while rotating it back and forth. Now shift in to forward gear and pull hard on the shift handle. You should feel an increase in drag while rotating the prop back and forth. This is the clutch dog bottoming out in the forward gear. Keep making adjustments until you can get a feel for it. Depending on how worn the linkage is you may not be able to get correct adjustment and have the gearcase go back to neutral in the neutral detent. Do the best you can and if necessary replace any worn parts necessary. Repeat the process. Remember to re-tighten both the adjustment screw and the clamp screw on the shift handle when done.
Now....just to be sure it is indeed jumping out of gear I would ask that you watch the shift handle when it jumps. the shift handle should jerk back toward neutral then back in to fwd. If it was not doing this then you may have a simple spun hub on the propeller. Let us know.