25hp Johnson pops out of gear

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lundwc16

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Haven't posted in a while as I just started using my 14' Mirror craft again. I have a 1977,25HP, electric start Johnson, tiller motor, mod # 25E77S. Under load the engine has started popping out of gear, & sometimes I get a "bang" like it hits an underwater object. I have taken the vertical access plate off the lower unit & checked the linkage connection, looks fine. I have drained the gear case grease, & it looks clean as it should. Anything else to check, or do I need to dig into the gear case?
John
 
This has been covered in here several times and you can do some reading up on it if you like,
What is going on is the clutch dog and forward gear lugs are no longer fully engaging. You are on borrowed time with them.
There is however an adjustment at the base of the gearshift handle. On the back side you will see an adjustment screw and a slot.
You want to loosen the screw and angle the shift lever backwards just a little. Tighten it back down. This will pull the clutch dog further into forward gear. Read on before you do this.
There is a way to tell when you have proper adjustment. Easy to do if you understand what I am telling you.
You can actually feel when the clutch dog bottoms out against the forward gear lugs.
Engine not running and spark plug leads disconnected!!!
While in neutral rotate the propeller back and forth by hand and get a feel for the smoothness and the amount of drag when doing this.
now put the handle in forward and do it again....should feel the same.
Engine back to neutral.
Now make an adjustment mentioned above but make a rather drastic adjustment at first. snug it down.
Now, with the shift handle in forward gear pull on the handle so it goes farther into gear and while holding it there rotate the propeller back and forth again. You should feel some additional drag. This is the bottoming I told you about.
Now, once you get used to the feel of a proper adjustment go back and make the proper adjustment so that you can just start to feel that bottoming when the handle is in gear but you are not holding it past what the detent will hold it.
Understand?
 
Thanks for the response, not sure if I understand sitting here, but I am sure I will have a better chance at understanding reading this again while I will have the motor in hand……John
 
The engagement faces of the drive lugs on both the clutch dog and the forward gear are now rounded off from jumping out of gear. They will need to be replaced or another gearcase sourced. If you choose the latter see if you can find one from 1982 or so. All of the improvements were in place by then.
Until then use the info I gave you. It will be temporary and may or may not work depending on the amount of wear.
 
pappy hit it on the head. once the dogs and gears become rounded, there is no fix. i even tried maching then straight again, but seems the heat treat is shallow and that repair didnt last long. if you are just running around a small area, the adjustment will get you some fishing time while you look for a good lower unit or gears.

after u fix it, dont be nice when you put her in gear, pop it in gear with speed and authority, it makes less grinding on the dog.
 
You doen't need to replace the lower if you don't want to. Here is the clutch dog with the shifter, you probably don't need the shifter and can buy just the clutch dog for about 100 bucks. You can also cross reference that part number on ebay and find a cheaper one. It will be used but will save you a few bucks. If you go that route just look at the pics and make sure the corners on the dogs (those two blocks sticking out one either side) are nice and sharp. Then as the other fellow said, put it in gear with a purpose, letting it grind is bad, a good solid "thunk" is what you want.

http://www.marineengine.com/newparts/part_details.php?pnum=OMC0390030
 
captain slow said:
You doen't need to replace the lower if you don't want to. Here is the clutch dog with the shifter, you probably don't need the shifter and can buy just the clutch dog for about 100 bucks. You can also cross reference that part number on ebay and find a cheaper one. It will be used but will save you a few bucks. If you go that route just look at the pics and make sure the corners on the dogs (those two blocks sticking out one either side) are nice and sharp. Then as the other fellow said, put it in gear with a purpose, letting it grind is bad, a good solid "thunk" is what you want.

http://www.marineengine.com/newparts/part_details.php?pnum=OMC0390030

good used lower unit is cheaper and easier. it also has gears worn at the same rate/bevel/yadayada. adding a new driven gear to a worn pinion may or may not be best.? on those motors, it is exremely easy to inspect the used motor or lower unit before paying. he will also have his original to rebuild. but i agree, if one can afford and obtain new gers, dog, shaft, bushes and bearings, seals, then it would certainly be best.
 
captain slow said:
You doen't need to replace the lower if you don't want to. Here is the clutch dog with the shifter, you probably don't need the shifter and can buy just the clutch dog for about 100 bucks. You can also cross reference that part number on ebay and find a cheaper one. It will be used but will save you a few bucks. If you go that route just look at the pics and make sure the corners on the dogs (those two blocks sticking out one either side) are nice and sharp. Then as the other fellow said, put it in gear with a purpose, letting it grind is bad, a good solid "thunk" is what you want.

http://www.marineengine.com/newparts/part_details.php?pnum=OMC0390030
Way off base.
For one he would need both the clutch dog and fwd gear. Chances are in that gearcase if he gets fwd gear it will be supplied with a pinion as well. Either way it would be a disaster to only install the clutch dog. Seals should be changed if going that route as well.
May as well source a complete gearcase.
Be careful what you type in this forum as "fact". We try and give the best advice possible without costing folks who are looking for help any unnecessary costs.
 
Pappy said:
Way off base.
For one he would need both the clutch dog and fwd gear. Chances are in that gearcase if he gets fwd gear it will be supplied with a pinion as well. Either way it would be a disaster to only install the clutch dog. Seals should be changed if going that route as well.
May as well source a complete gearcase.
Be careful what you type in this forum as "fact". We try and give the best advice possible without costing folks who are looking for help any unnecessary costs.

Pappy:
Slipped hub???(!!!)
More likely fwd. gear & dog replacement, but used to occasionally run into a bad prop...

-W
 
Pappy said:
Nope............
A hub slipping does not produce the "bang" that he described. Hubs, when they slip, feel like you got weeds around the prop.

ha, remember the 65 hp electric shifts? they would sound like a machine gun when they got bad.
 
Pappy has it right about the problem, all of it is good advice and probably the best way to make sure it is right if you don't usually do your own repairs. However, I have tried finding lower units for those motors, and they may be hard to find or can be expensive. I had the same issue an old Evinrude 25. Didn't know about adjusting the throw, but replacing the dog and forward gear worked just fine. It might have been a little stiff at first, I don't recall, but I never had the problem again. So, if he can't find an inexpensive used lower unit, the gear replacement is an option. Also sites like Ebay or the OMCI (Outboard Motor Club International) are good places to look for good used parts. Just look at the pictures carefully before you buy or make sure there is a return available, because you don't want to buy one that is as bad as yours.
 
old_fart said:
Pappy said:
Way off base.
For one he would need both the clutch dog and fwd gear. Chances are in that gearcase if he gets fwd gear it will be supplied with a pinion as well. Either way it would be a disaster to only install the clutch dog. Seals should be changed if going that route as well.
May as well source a complete gearcase.
Be careful what you type in this forum as "fact". We try and give the best advice possible without costing folks who are looking for help any unnecessary costs.

Pappy:
Slipped hub???(!!!)
More likely fwd. gear & dog replacement, but used to occasionally run into a bad prop...

-W

Had more than one instance where a bad hub felt just like a bad clutch dog.
And, as best I remember, it was on 40HP and less (this being the days before
thru-hub exhaust).
Might have seen a few bigger motors too (been over 40 years since I made a living doing that),
but the rubber in the hub would slip a half-turn then grab. I want to say when you looked at
the side facing the gearcase, the hub wasn't well centered in the aluminium propeller any more...

I imagine running a jumping clutch dog for a while can break the hub loose and
reproduce the jumping symptom...

I've been far happier dealing with Velvet-Drive and a .002" feeler gauge...

-W
 
poorthang said:
Pappy said:
Nope............
A hub slipping does not produce the "bang" that he described. Hubs, when they slip, feel like you got weeds around the prop.

ha, remember the 65 hp electric shifts? they would sound like a machine gun when they got bad.

Had one of those show up every spring stuck in forward gear...
Boss told the guy not to leave it empty in the fall...
Gearcase finally grenaded and the owner bitched&moaned to Johnson 'till they got tired of
listening him, replaced it, and told him never to come back... (55HP in like '72 or '73)

Always check for bad "Dog Nuts" on those :)
(If you know what "dog nuts" are, you're older than dirt...)

-W
 
yep, dirt is new. lol my worst headache on those was the oil soaked wiring that ran from the power head to the foot. i dont reckon i remember dog nuts tho. that was only 50 odd years ago.
 
Just throwing this out there, for outboards that are hard to get parts for, or just aren't worth what a set of gears cost, a good machinist can build up the dogs and mill them back to square.

I had it done on a 75hp Suzuki, wasn't worth spending $1000 on a new gear set plus all the labor of reshimming them. Machine shop did it for $200, ran it for three seasons without a problem.

Not the "right" fix, but gotta do what you gotta do sometimes.
 
old_fart said:
poorthang said:
Pappy said:
Nope............
A hub slipping does not produce the "bang" that he described. Hubs, when they slip, feel like you got weeds around the prop.

ha, remember the 65 hp electric shifts? they would sound like a machine gun when they got bad.

Had one of those show up every spring stuck in forward gear...
Boss told the guy not to leave it empty in the fall...
Gearcase finally grenaded and the owner bitched&moaned to Johnson 'till they got tired of
listening him, replaced it, and told him never to come back... (55HP in like '72 or '73)

Always check for bad "Dog Nuts" on those :)
(If you know what "dog nuts" are, you're older than dirt...)

-W

Most people called them "Monkey Balls"
Yes, I remember them well.
 
Pappy said:
old_fart said:
poorthang said:
ha, remember the 65 hp electric shifts? they would sound like a machine gun when they got bad.

Had one of those show up every spring stuck in forward gear...
Boss told the guy not to leave it empty in the fall...
Gearcase finally grenaded and the owner bitched&moaned to Johnson 'till they got tired of
listening him, replaced it, and told him never to come back... (55HP in like '72 or '73)

Always check for bad "Dog Nuts" on those :)
(If you know what "dog nuts" are, you're older than dirt...)

-W

Most people called them "Monkey Balls"
Yes, I remember them well.

How's 'bout that one instructor in Waukegan (JOhnson service school) that had a foot long allen key in his
kangaroo pants pocket. He could mess the points up on a '68 55HP in about
three seconds flat (And I can't remember his name)...
On those 3-cyl motors you had to pull the flywheel, remove the stator &distributor
cap to get at them little bas***ds (the points). He has removed a breather from
the cap that lined up perfectly with the adjusting screw...
Lesson Learned: Service School instructors can NOT be out-smarted, they're
the most devious bas***ds on the face of the earth when it comes to getting
their students to read & follow the service manual :)

-W
 

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