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1968 evinrude fastwin 18hp. Need help!

P

Poepoe3

New member
I just picked up a 68 evinrude fastwin for 50bucks. I was out testing it and it seemed like it was riding well but all of a sudden the prop stopped spinning. There wasn't.a loud bang or anything. When the motor is off the prop will turn in reverse and in forward. Would like to know what the possible problems could be. And if it's worth having it fixed! Thanks!
 
Check for a broken shear pin in driveshaft,not sure if that year has one,remove cotterpin,nosecone,and prop,take a look
 
I think it is! There should be a pin that sticks through the driveshaft and the prop has a slot to fit it right? I turned the driveshaft in reverse and forward and it turned a little and stopped. Is this the culprit?
 
Correct, should be in three pieces now that it sheared,Grab a few new ones at dealership and make sure you don't slam her in forward gear at higher than normal idle speed otherwise you will be replacing pin again, Make sure slot in prop. is not excessively worn, "free play". That shear pin takes the brunt of underwater impact instead of lower unit and prop to some extent
 
johnnygjr said:
Correct, should be in three pieces now that it sheared,Grab a few new ones at dealership and make sure you don't slam her in forward gear at higher than normal idle speed otherwise you will be replacing pin again, Make sure slot in prop. is not excessively worn, "free play". That shear pin takes the brunt of underwater impact instead of lower unit and prop to some extent
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Thank you for your help I really appreciate it!!
 
The shear pin is actually a steel pin.-------Called a drive pin.-----------Possibly a brass pin was installed.-------------Check for a spun rubber hub inside the prop.
 
Most likely the shear pin was the entire cause of the problem. Have you checked the lower unit gear oil??? (very important) After you have checked the gear oil, water test it again for any slippage in the prop hub.
 
bobbyc said:
Most likely the shear pin was the entire cause of the problem. Have you checked the lower unit gear oil??? (very important) After you have checked the gear oil, water test it again for any slippage in the prop hub.
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I will check it! To check it is the flathead screw on the lower unit right? One is to drain and one is to check? And what kind of gear oil is recommended for this motor?
 
80w-90w gear oil,upper screw is vent&level, bottom screw is where she is filled from till oil comes out vent hole,then replace top screw with a new nylon washer,followed by lower with same. There is a pump kit that fits on quart bottle for this application sold at auto parts stores and marine supply
 
johnnygjr said:
80w-90w gear oil,upper screw is vent&level, bottom screw is where she is filled from till oil comes out vent hole,then replace top screw with a new nylon washer,followed by lower with same. There is a pump kit that fits on quart bottle for this application sold at auto parts stores and marine supply
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I replaced the drive pin today and checked the oil. There was plenty of oil in there. Maybe too much. Some flowed out when I took the top plug out. I am going to water test this weekend hopefully! Thank you for all your help I really appreciate it!
 
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