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72 Evinrude 25HP slipping out of gear under load

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scarpozzi

New member
This engine had this problem 23 year ago and it's been sitting ever since. I replaced the prop with a new one because the old one obviously had a spun hub. You could see where the bushing had slipped and the center was sticking out.

I took it out yesterday and started it up for the first time. I got the engine good and warm and decided to give it a try because I was able to pull start it easily after warm up. As soon as I opened it up, it popped out of gear. It's a manual shift tiller drive. I know the shift rod was right so I drained it and can see the a rounded edge on the clutch dog. The forward gear has 2 slight rounded edges, but they aren't near as bad as the clutch dog.

$150 for a replacement...Is it possible to just flip the clutch dog and run it backwards? Reverse doesn't require the high rpms forward does....Just curious if that will buy me time and get more wear out of the part.
 
ForwardGear.jpgClutchDogForwardGearSide.jpg

Here's what they look like. I drew a yellow box around the rounded corners. The clutch dog appears more rounded than the forward gear, but you can definitely see a rounded corner on each. I really would have expected more excessive wear before these parts would fail. I notice that this is a common issue with these engines, but wondering how *normal it is. I can imagine shifting when rpms are too high or having an engine tuned to idle high would wear the parts more quickly.

I understand the dog is just part of the problem. I'm just curious if I can make it work for a while without dropping $300. Because of the limited surface area of metal involved that's possibly causing my issue, I'm not going to risk buying a used gears, unless this doesn't appear that bad to others. Thanks for any input.
 
Check to make sure the brass connecter is properly assembled.-----Then check the ADJUSTMENT at the shift handle.----Those parts do not look that bad in the pictures.
 
racerone said:
Check to make sure the brass connecter is properly assembled.-----Then check the ADJUSTMENT at the shift handle.----Those parts do not look that bad in the pictures.
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I've read a lot about these parts going bad. It seems the issue isn't just one going bad, but both slipping together. Neutral to gear was working fine.
I'm the one that installed the shift rod The clutch dog and forward gear both have 1 rounded edge that's worse than the other.

I rubbed the inside of the forward gear with a 1/4" drill bit and installed the clutch dog backwards. I reused the 'new' gear oil, so no loss there. I just need to take it to the lake and give it a try.

I went ahead and ordered all new gears, forward/reverse/clutch dog for about $260, so we'll see how long this works.
 
What I suggest is new detent balls and spring too. That's only a few extra bucks. The spring can get weak especially if there was ever a time where it had some rust starting in there. I'll buy those old parts from you......they actually look pretty good for reconditioning. You take pay pal?
 
timguy said:
What I suggest is new detent balls and spring too. That's only a few extra bucks. The spring can get weak especially if there was ever a time where it had some rust starting in there. I'll buy those old parts from you......they actually look pretty good for reconditioning. You take pay pal?
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I have the old ones installed with the clutch dog reversed. I plan on testing it out and seeing if it will run like this for a while. In my opinion, they do need to be reworked and I can see damage on them.
 
timguy said:
Okay let us know how it goes. Thanks, Tim
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I went ahead and ordered a new clutch dog, forward and reverse gear. They were $130,$104, and $20, respectively from 3 different sources. I figured those parts are going to be harder to come by in the future, so I can oil them and shelf them if flipping the clutch dog doesn't work.

I took the boat out this morning to show my dad how the engine was running and tested it. I still have a fuel issue somewhere because it bogs down when under load. It may need another new fuel pump because it revs fine at the dock. Reversing the clutch dog seems to have fixed the slipping out of gear issue. I feel good about it because I may get another 2-5+ years out of this set before I need to swap it out.

If someone else reads this thread, be aware that flipping the clutch dog may save you some cash and provide your gearset a few more years before it needs to be replaced. It's worth a shot if you have an issue with it popping out of gear under extensive load at higher RPMs. Mine still needs more testing, but I'm like 95% confident after seeing this motor NOT slip today since it has the last 5 times it's been in the water (including 4 times 20+ years ago)
 
Sgcp1933 said:
Where did you find these parts, I’m have the same issue
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eBay and various marine parts stores. I still have my gearset and haven't swapped them yet. I found that I was able to flip the part that was rounded and it fixed the issue for me. It was only popping out at high rpm/top speed. Reverse doesn't put that kind of load on it since you only back up at low rpm. See if you can flip yours after inspection....might save $$$.
 
Keep in mind that bad motor mounts can also cause this condition on these motors to jump out of gear. I agree, that wear on the clutch dog and forward gear does not look that bad.
 
scarpozzi said:
eBay and various marine parts stores. I still have my gearset and haven't swapped them yet. I found that I was able to flip the part that was rounded and it fixed the issue for me. It was only popping out at high rpm/top speed. Reverse doesn't put that kind of load on it since you only back up at low rpm. See if you can flip yours after inspection....might save $$$.
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okay thanks I’ll check some other things out. I found a boat yard near me that says he has a set of good gears for 50$ so I may see if there better than mine.
 
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