Evinrude E-NATION, for those dedicated to water, power, fishing and fun
Posts: 1
Registered: ‎01-01-2020

E-tec 40 (E40DPGLAGD) EMM ground stud corrosion

Has anyone else found corrosion on the grounding stud for the EMM and other components?  I found it on the stud's threads where it screws into the block (through the starter solenoid).


There was a bunch of aluminum oxide in the hole where the stud goes into the block.  No sign of any anti-corrosion treatment.  The oxide might have caused enough voltage drop to keep the EMM off intermittently.  I did find anti-corrosion compound on the battery cable ground stud, but the power has to go from that stud to the block to the grounding wires for the EMM and other system components.


I also found no anti-corrosion treatment on the ring connectors that attached to the studs, other than black paint over the ground connections.



Posts: 946
Registered: ‎08-20-2017

Re: E-tec 40 (E40DPGLAGD) EMM ground stud corrosion

I have not seen any stud corossion. Most of the electrical contact points have "star" washers for positive contact. The "black paint" is liquid electrical tape.
If there are signs of corrosion under the cowl you should be looking for the root cause such as leaking cooling system components or external sources which are causing water intrusion under the cowl.