1974 Evinrude 15 hp internal trouble

[Duxnbux]

My 15 came apart on the inside and I wonder if it is savageble. One of the 2 screws that holds the top piston arm to the crankshaft backed itself out while it was powered. The motor of course quit. I removed the top piston and got the screw and other parts out. The cylinder wall on the top doesn't seem to be scored and I don't think there was any shaft damage. The bottom piston is fine and has good conpression when you pull the rope. Can I just replace the top piston, arm and rings and be OK. Thanks

 

[rickdb1boat]

Re: 1974 Evinrude 15 hp internal trouble

As long as the Cyl. Wall is OK, you can just replace the one Piston. You might want to have it honed out to be sure it's not "Out of Round".

 

[petryshyn]

Re: 1974 Evinrude 15 hp internal trouble

Sounds like you were lucky. Be sure there is no marks on the crankshaft journal. If there is, you must polish them out with fine crokus cloth...<br /><br />When you install the new rod bolts, use red loctite. I'd do the other rod as well. Be sure to torque them appropriately

 

[Boatist]

Re: 1974 Evinrude 15 hp internal trouble

Duxnbux I would replace any thing you find damaged and hone both cylinders and install new rings. As long as you have it apart remove the carbon and replace the rings. They just do not cost that much.