1962 Johnson 75 hp Sea Horse Prop issues

[daveydb]

I purchased a boat that came with the 1962 super sea horse 75 hp electric shift motor and am wondering how to remove the prop. There is a black tapered (I think plastic) thing behind the prop. I am not used to this and would be able to remove it if it was just a normal nut. How do I go about taking this off?

I am removing it because I took the boat out and the engine started right up, but then I took it out of neutral and nothing happened. The engine would rev up but the prop wasn't turning. I was going to take off the prop and check if it was spun. I can also turn the prop very easily even when it is in gear. Any ideas? Thanks

Dave

 

[ICEMAN]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

This tapered thing is a cone. I believe there were two styles used back then, either way, there should be a cotter pin going thru it. if it is totally round, with no flat edges, it should just come straight off, after removing the cotter pin, the other style has flat sides, this one is screwed onto the propshaft. then there will be a shear pin on one side of the prop, i think that one is on the outer side.

 

[tashasdaddy]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

all i have ever seen have the cotter pin thru it, remove the pin cap side off, then prop and prop shaft have a hole thru them, that a shear (drive) pin goes thru. it sure sound like if did it's job, by breaking and protecting the lower unit.

i will try to get a picture this morning.

 

[F_R]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

As already said, the cone (they actually do call it a nut in the book) just slides off after removing the cotter pin. ALWAYS use a new stainless steel cotter pin. That is the only thing keeping the nut (and prop) on.

However, a real quick check for what is wrong is to see if the nut is able to turn without turning the prop. The nut is keyed to the shaft so if it is turning when the control is in gear, the shaft is turning too. It shouldn't. Well, let me qualify that statement..it will turn with some resistance in one direction only.

If the prop will spin around freely without turning the nut, the drive pin is broken.

Anyhow, it's all obvious when you remove the nut and prop

 

[Evinrude Boater]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

Welcome to iboats, Dave. You'll find lots of good advice here for your motor.
Maybe it wasn't in gear as you thought. If you could turn the prop easily in gear it would be all wobbly and loose. Even when the hub has lost its grip they're usually still quite tight to move by hand.

 

[daveydb]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

I thought it was in gear when I checked this. I moved the control from the neutral position to forward and reverse but the resistance on the prop didn't change at all. Is there a linkage that I could be missing that wouldn't allow it to really change gears. We took it out on the lake and got it started, then moved out a neutral and the motor revvs up but the boat doesn't move. I am going to try and get the muffs on it and see if the prop will actually move out of the water. If the motor responded to the controls wouldn't that mean it was taken out of neutral, or am I missing something?

Thanks for all of your help.

 

[F_R]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

You gotta remember this thing is electric shift. There are no "linkages". As I tried to explain earlier, with the control in forward or reverse gear position (and the key turned on) the prop shaft should not turn freely. If it does, you have an electrical problem.

However, same scenario, control in gear and key turned on, If the prop turns freely but the shaft (nut) does not, then you have a broken drive pin.

Can't explain it much simpler.

 

[daveydb]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

I guess I didn't realize that the key needs to be turned on. I will try that later today and see what happens. Thanks

 

[daveydb]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

Ok, I turned the key on and put it in gear and the prop shaft wouldn't turn. The prop is still spinning even when in gear so I guess that means I have a broken shear pin. That saves me a lot of headache. Thank you guys so much for walking a novice through all this. I am going to check the shear pin tomorrow if I can figure out how to get the cone off. I took the cotter pin out and it doesn't want to slide off. I am going to try attaching a pic so it may be a little easier to tell what I am dealing with. I don't know if it is threaded and just needs something to grip it to turn it, or if I should just try to muscle it off. With it in gear, would I be doing any harm to the driveshaft or anything else if I just tried to unscrew it (if that is what it needs)? I would normally think to block the prop to provide the counterpressure but since the prop is spinning that isn't going to work. Thanks for all of your help and any advice on how to get this off would be greatly appreciated.

I am going to let everyone I know that has a boat know that this is the place to come for answers. What a sweet site.

 

[tashasdaddy]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

use an OEM shear pin not a hardware store one. or you will be changing one on the water. always carry a spare.

 

[F_R]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

It does NOT screw off. It pulls straight off. In fact it CANNOT rotate on the shaft because it is keyed. It is probably stuck from a bit of rust. Use a couple of screwdrivers to pry it off.

 

[Willyclay]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

While your picture is a little fuzzy and I cannot be certain, it appears that your prop nut (aka cone) is too large for the prop installed and may not be the correct part number. When I had a 1962 Johnson 75HP electric shift motor, a dealer found me a prop for skiing and the hub was smaller than the gearcase. He called it a "Ski-Do" prop and it had a different nut/cone. Regardless of the prop and nut, only a cotter key holding it on. Good luck!

 

[F_R]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

Sharp eyes, Willy. I think you are correct. A large hub nut on a small hub prop. The prop and nut are supposed to fair together.

 

[daveydb]

Re: 1962 Johnson 75 hp Sea Horse Prop issues

UPDATE:

So, I finally got the prop off (after unsuccessful pulling and even trying to unscrew it gently) by using a hammer and a peice of wood. Sure enough, the drive pin had sheared and was actually missing. I went down to the Marine store in town and they finally found a OEM one that I purchased. I am going to be putting it back together with some grease and see how we fly. They were pretty surprised when they saw the prop and it was bronze. I don't think I want to buy OEM pins, they were a bit more pricy. Does anyone know where I can find an aftermarket #13 drive pin. I beleive that was the number they said I needed.

Again, thanks for all of your help. It saved me a lot of headache and time.