1974 Johnson 50hp Stuck.

[Bosunsmate]

I cant tell from those photos, just open it up as you say and inspect.

 

[gm280]

I have been watching this thread for a while. If I am correct, your original problem was the lower unit was stuck and would not come apart. And now you have that apart. So that is good news and you should be able to look at the splined top section and see it there is any corrosion either on the drive shaft side or engine crank side. If both look okay, then you need to turn your attention to the power head.

And I take it the power head is seized up as well. So your only option now is to follow the shop manual to disassembling that power head. And I would totally disassembly the head and replace any parts that are not in spec. If you are willing and have the mechanical knowhow, you can make that engine run perfectly again. It is really up to you.

So work to disassembly the power head using the shop manual and see what has it seized. So many things can seized one, but usually the piston and rings are the typical culprit. But even with the piston and rings being seized, there is usually a little endplay with the crank. So if this is solid without any endplay, I think other things are rusted solid as well. But that doesn't mean if can't be fixed. JMHO!

 

[racerone]

Perhaps put a big socket on the flywheel nut and see if the flywheel will move at all.-------------The pictures do not indicate a huge rust problem.-------You have reported that the flywheel will not BUDGE even a little bit ?

 

[Chrisravosa36]

I have been watching this thread for a while. If I am correct, your original problem was the lower unit was stuck and would not come apart.

you can make that engine run perfectly again. It is really up to you.

Perhaps put a big socket on the flywheel nut and see if the flywheel will move at all.-------------The pictures do not indicate a huge rust problem.-------You have reported that the flywheel will not BUDGE even a little bit ?

Should I try an impact wrench on the flywheel nut, just and idea. I currently dont have that big of a socket, I belive its 1 1/2, and all I have is 1 1/4, Il go by one today and see what I can do. And Gm the original topic was the power head I thought was stuck, no I suspect it is the bearings, thanks to racerone. Also, I am trying to et the motor to run great again, that would be idea. Im hoping I will not find much scoring on the pistion walls. I would like to take it slowly, my first goal is to get it free, then I go from there, but i like your attidude! :joyous:

 

[racerone]

The socket is 1-5/16"---Try a hefty screw driver using the starter motor ( put it back on ) and see if you can move the flywheel .---Pry gently !

 

[Chrisravosa36]

Could I use a crow bar? or is that to much? I just dont have a big hefty screwdriver.

 

[gm280]

Chris, I used a 1/2" Craftsman pneumatic impact gun to tighten the center bolt on the fly wheel puller. I used grade 8 bolts for the three bolts that threaded into the flywheel (about 1/2") and then tighten the center bolt until I could tighten it anymore. Then I got out the pneumatic impact gun and used that. It still took a long time but it did let go and snapped like it broke. But it was just the flywheel coming loose. JMHO!

 

[oldboat1]

Don't think I would pull out a crowbar or a rattle gun to bust the crank loose, though -- might carefully try a breaker bar and socket to try the crank, steady pressure with some feel to it. The rattle gun is useful when it's time to remove the flywheel nut. (Need to buy the big dog phillips and flat head screwdrivers for future use, btw.)

I haven't done the rattle gun on a flywheel puller -- yet. Down tight with a wrench, two whacks with a 2 pound hammer (repeat/wait/repeat). Don't doubt reports of rattle gun success, though.

 

[Chrisravosa36]

Rattle gun, lol! Sure sounds like a mean snake rattle! Never heard it called that, but I think I will start doing so, I bought the harbor freight wheel puller, only 13$, I tried it out tonight, the rattle gun helped getting the nut off, and I tried the puled once, but deiced to wait till I had more time to do it. im sorrta worried if I apply to much torque, something will break and Il get injured. So how much lbs of torque should I put on the flywheel before I start banging on it?

 

[flyingscott]

Do not use the impact gun on the flywheel puller. You should be able to tighten it by hand get a strap wrench for the flywheel. Using the impact gun is when bolts get stripped and parts go flying. Do what oldboat said tighten it down and whack it with a hammer.

 

[Chrisravosa36]

Thanks for the advice Scott, I tightened it pretty much all the way with the torque wrench, nothing moved. So il try hitting it next, where should I hit, the center or the wheel puller? the flywheel itself?

 

[oldboat1]

yeah, yeah. torque wrench, impact wrench. It rattles.

Don't hit the flywheel! Bolts have to be straight and even. It's the center bolt that tightens down, not the little bolts (which lift up). Whack it once or twice straight down, then tighten it down again, and hit it again. By the way, be sure to have the nut on a few turns to protect the shaft and to keep the wheel from flying up when it lets loose (not sure if that was noted -- probably was). Don't worry about torque values (another reason to use the wrench rather than that strange gun thing this time. Get the hang of it.)

 

[Chrisravosa36]

So I should tighten the puller, losen it then hit the flywheel? Im confused?

 

[Keyboardman]

Hit the center bolt on the puller,then tighten it and hit it again. It took a bit of work to get the one off my old 50hp. Also, be sure that the three smaller bolts are screwed down as far as they will go. I didn't do that and they pulled right out and goobered up the threads on the flywheel.

 

[gm280]

Hit the center bolt on the puller,then tighten it and hit it again. It took a bit of work to get the one off my old 50hp. Also, be sure that the three smaller bolts are screwed down as far as they will go. I didn't do that and they pulled right out and goobered up the threads on the flywheel.

I have remove OB flywheels and with some of them, you DON'T thread in the three smaller bolts as far as they will go. Some flywheels are threaded all the way through and if you tighten them as far as they can go, you will be ruining parts underneath the flywheel. The usual technique is to thread then about 1/2" or so and no further. The center bolt does the real work. JMHO!

 

[Keyboardman]

I have the same exact engine Johnson 50esl74m. The bolt holes do not go all the way thru the flywheel. They are about 1" deep. I made the mistake of only going down about 1/2" and they pulled out.

 

[Chrisravosa36]

Ok, I also have to get the lower pan/cowling off, anyidea how that comes off, I didnt see anything in the manual about it?

 

[Keyboardman]

Section 6-8 figure 6-14 in the factory manual shows an exploded view. Did you get the original Johnson factory manual?

 

[Chrisravosa36]

Il look again, I dont remember seeing it, today Id like to get that off, get the flywheel off and the powerhead opened up to see whats causing this... I still dont understand the "timing" very well, can somebody try to explain that to me, I read about it in the manual, but dont understand it that much, will I have to fix that after I do all of this?

 

[flyingscott]

Just tighten the puller until it is tight as you can get it and leave it tight then wack the center big bolt on the puller with a hammer just like driving a nail. Make sure they are all even that's important. I use just a plain jane carpenters hammer 16-20 oz. The lower pan wont come off until the powerhead is off. The lower shroud under the pan comes off with 8 bolts. 3 on each side and 2 going down back under the hood by the head. Then you will see the bolts holding the powerhead on. Now I don't know if that model has this but worth checking. Under the head there might be a stud for the powerhead take that nut off. Timing will come at a much later date.