1978 Johnson 35 hp Lower Unit

Well, I've had a string of bad luck on outboards.

I purchased a 1978 Johnson 35 hp motor last month. It starts up great and shifted well on the muffs. However, when I took it out on the lake, it slips out of gear at about 15 mph or so. It feels like I'm hitting a stump. I believe the issue to be a clutch dog. It seems like that was a real issue with this model of lower unit.

After doing some research, I'm not quite confident enough to get in to the lower unit to change the clutch dog. The bearing housing pull intimidates me a bit and I'm most worried about getting everything back together. Additionally, it looks like a new gear set runs about $300. My thought is, at that price it would be easier and not too much more money to find a used lower unit. BUT, I've scoured the interwebs and haven't found a single compatible lower unit.

Three questions:

1. Honestly, how difficult is it to get into the lu and change the clutch dog? I'm decently mechanically inclined, and don't mind doing most of my own work.
2. Does anybody happen to have a working LU for this motor sitting around?
3. Does anybody have a secret source for used LU's that I haven't found?

Thanks guys!

do you have a picture of the motor I think I had 1 with a bad head

hardwatergrampa said:

do you have a picture of the motor I think I had 1 with a bad head

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Sure thing, here is a pic.


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mine was a evinrude long shaft ill try to check to see if I still have it this week is yours long or short

That would be great, I appreciate it.

This one is a long shaft, so that would likely work.


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Pappy said:

Post the model number of your engine.

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Thanks, will do when I get home.

Off the top of my head, model 35EL78R. Will update for sure when I get home.


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Figures I found one of the only bad Johnson’s out there. [emoji849]

The powerhead seems to be in great shape. The block is very clean, no flaking paint or anything. It pumps water pretty strong as well. It seems to run well excepting the lower unit issues.

Thanks for the heads up though, I’ll be sure to keep an eye out for that issue.

A guy has to fish, so to this point I’ve just been idling around the lake to my spots.


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What is the fix for that obsolete water tube coupler if it is melted?

Thanks for the reply.

haven't had time will try in the morning and seeif I can get model no. this motor did over heat

maybe some 1 can tell if it will fit ser #j30elcrr mod # is e600 4748 have pictures on my phone but don't know how to post them ill have the grandson do it this weekend

hardwatergrampa said:

maybe some 1 can tell if it will fit ser #j30elcrr mod # is e600 4748 have pictures on my phone but don't know how to post them ill have the grandson do it this weekend

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If you want to send the pics to 704 223 4637 I will post them for you.

I have replaced the dog on a '78 15 horse and the gear set on a '92 30 horse (Johnsons). Takes about a dozen cuss words is all.

@Rocs my biggest issue at this point is cost. I’ve read a few places that if the clutch dog is bad, chances are that the gears are as well. A new gear set is about $300. At that price I’ll be looking at new motors! I only paid $400 for this motor to begin with.


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DiveLiberty said:

@Rocs my biggest issue at this point is cost. I’ve read a few places that if the clutch dog is bad, chances are that the gears are as well. A new gear set is about $300. At that price I’ll be looking at new motors! I only paid $400 for this motor to begin with.


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And many times you are correct. But you paid $400 for a motor with issues. I don't know about Mo. but around here you won't get a known good motor that size for $400. or no where near it. You would be looking at a couple thousand. Sometimes it is better to go ahead and fix what you have.