HELP 1973 evinrude 50hp breacking fly wheel key

[crabguy]

hello my name is guy and i found this motor for $100 and they said it ran when i got it home hooked it up and tried to start it and would not start.me and a friend was testing every thing and found that the key that holds the fly wheel in time was sheered so i went to the dealer and got one put it in and it started after 2 crancks and ran like a champ put it on the boat and took it to the lake and it started good winth some ajustments and and ran backed it off the trailer it went into ger hard but still worked put it in gear and started to go got out of the 5mph and started the throghtle up got half way there and the motor raced and then died and would not start again it was tring to but was acting like it was out of time and im perrty shure it is what could have coused this and is it an easy fix?

 

[samo_ott]

Re: HELP 1973 evinrude 50hp breacking fly wheel key

Did the key break the second time? This usually happens because it was not torqued down enough. I don't know that model but it will probably range from 50-100 ft lbs. Make sure it is to spec or it might shear again.

 

[F_R]

Re: HELP 1973 evinrude 50hp breacking fly wheel key

Unbreakable flywheel rules:

The crank and flywheel tapers must be clean and dry

They must not be damaged. Period. That includes wallowed out key slots.

You MUST use a torque wrench to tighten the nut to specs.

Failure to observe the rules will result in a sheared key at the least, and a destroyed crankshaft and flywheel at the worst. Every time it shears the key, the damage gets worse. After a few times of that and you might as well put it out at the curb for the trash pickup.

 

[ezeke]

Re: HELP 1973 evinrude 50hp breacking fly wheel key

100 to 105 foot pounds.

 

[crabguy]

Re: HELP 1973 evinrude 50hp breacking fly wheel key

thank all of you for your help yes the key was sheered but spent most of the afternoon sanding both surfases smooth and we will try it to morrrow i also went and bought a manual and it is 100-105 fps i also canged the oil in the lower unit for good measure im crossing my fingers