Broken Crankshaft key.

[Glenn Romain]

Well wile im waiting for decals for my 1955 15HP Evinrude i decided to take a look at a 1963 Johnson 18hp i bought off a guy last winter for 50 bucks
When i bought it he said he had it running on the river and it just quit and that he did not have the time to look at it .
Well to me he did have a look at it and heres why , i strarted by removing the recoil but noticed right away that the 3 bolts are loose ,so i think no problem maybe the guy started to look at it . Humm next i try the Crankshaft nut ,again loose. Then i install my puller and after two turns of the big center bolt the flywheel is loose ,now i know he went digging to find the problem and i guess he stopped there when he saw that the coils were all cracked and gummy with some kind of tar . Then i start looking for the Crank key and cant see it so i get a light for a closer look and its there alright but broken , i found both pieces and took some photos so you guys can give me advice. Oh and this motor has a electric start could it be that he tried to start it to often and that the starter broke the key ? Im open to all your toughts .

Thanks in advance Glenn the Outboard noob

 

[Glenn Romain]

Re: Broken Crankshaft key.

Oh and if this is still good to go were do i pick up a new key ?

 

[Joe Reeves]

Re: Broken Crankshaft key.

Flywheel key #307480 should be available at any dealership, possibly on this site.

CORRECTION: Flywheel key is part number 120395 not 307480 as mention above.

Install it so that the flat edge of the key is vertical with the engine, NOT aligned with the crankshaft taper.

 

[Glenn Romain]

Re: Broken Crankshaft key.

Thanks for the quick reply Joe ,i found key number 120395 in the parts book online guess it changed over the years . Any idea on what caused the key to break ? I found one on Ebay for 2.99 but the guy want $ 50 to ship it lol .

 

[F_R]

Re: Broken Crankshaft key.

120395 is the correct number. Get it from any Evinrude dealer. List price is $3.33.

I don't know which is the word I want to use. Sad? Angry? Anyhoo, I preach and preach and the service manuals are very clear, and people still continue to destroy those old motors that way. There is no excuse for shearing flywheel keys, it is the direct result of improper flywheel installation.

When installing the flywheel, the tapers must be clean and dry and in perfect condition. And you MUST use a torque wrench to tighten the nut to 40-45 ft lbs. If you ignore this advice, what you see here is the result. Fortunatly the crank looks ok, but the keyway in the flywheel is battered. You need a flywheel.

 

[Glenn Romain]

Re: Broken Crankshaft key.

Ack thats not something i wanted to hear F R does it realy look that bad or could i take a chance on it .

 

[freddyray21]

Re: Broken Crankshaft key.

the one I am working on now the guy did not get it torqued down right and it spun 180. He got frustrated and took a hammer to it. I had to cut what was left of it off. Tomorrow when the used flywheel, mag plate, shift handle and belly pan get here I get to start putting it back together. Don't loose your patience and take anger management.

 

[Joe Reeves]

Re: Broken Crankshaft key.

Glenn.... 120395 is the correct number of the flywheel key. I was looking at a later model, sorry.

 

[samo_ott]

Re: Broken Crankshaft key.

Wow, I was thinking the flywheel did not look that bad. From my understanding the key is only there to line it up, not actually hold it in position. It is the force on the taper that holds it in position thus as long as the key is there to line it up and then you torque it correctly it should work fine. If it were mine, that's what I would do.

And I was out in my '62 18hp today

btw, nice big clear close up photos.

 

[Glenn Romain]

Re: Broken Crankshaft key.

Lucky Dog Samo , i think i finally found out why the key broke . The prop was all broken so i figure the guy that had this motor before me did not use the proper shear pin and hit something real hard ,well hard enough to break the key and prop.
Was lucky enough to find a key after my second stop at local engine shops today

Oh and the photos were taken with a TZ5 Panasonic it has a closup mode thats does the trick

Again thanks for the replies guys