Copper crush washers ok to use?

[Rob406]

I just changed the lower unit oil on my (new to me) 96 evinrude 50 spl. I bought evinrude plastic crush washers, which did fit the drain plug. But the vent plug was different and all i had on hand was my copper crush washer set. Talk is cheap so i thought i’d ask the board. By the way the vent plug put up a good fight to break free and i replaced with a 1/4-20 stainless phillips pan head bolt. Found an allen head as well, but i felt it didnt have enough of a shoulder. Thoughts?

 

[Scott Danforth]

Copper and aluminum do not like each other from a galvanic corrosion point of view

 

[tphoyt]

If your in salt water copper and aluminum don’t go well together at all and the electrolysis will eat your lower unit in short time

 

[Rob406]

Copper and aluminum do not like each other from a galvanic corrosion point of view

Thanks, i wasnt aware of that. Is plastic the best option then? Hopefully I can find something at the hardware store. They have the white poly washers but not sure if they are intended as a crush washer

 

[Rob406]

If your in salt water copper and aluminum don’t go well together at all and the electrolysis will eat your lower unit in short time

Fresh water only, fortunately.

 

[Scott Danforth]

Even in fresh water galvanic corrosion will be an issue

Use the plastic crush washers

 

[Rob406]

Even in fresh water galvanic corrosion will be an issue

Use the plastic crush washers

Okay will do. Since it’s just the vent plug, can i just pop it off, replace washer and reinstall?

Also does it have to be a specific crush washer? Ace hardware has the plastic washers that look exactly the same as the evinrude washers, but they are not sold as a crush washer. Not really sure what they are for.

 

[Scott Danforth]

The plastic washers at Ace are nylon. Nylon is hygroscopic (absorbs water)

Not sure the johnyrude crush washers are nylon (I don't know what they are made of)

 

[Rob406]

The plastic washers at Ace are nylon. Nylon is hygroscopic (absorbs water)

Not sure the johnyrude crush washers are nylon (I don't know what they are made of)

Jeez glad i asked. Well i hope evinrude knows that. Ok so my options are the fiber drain plug washers at ace (which i assume would be a no go) or i could try napa to see if they have a 1/4” plastic crush washer (usually blue in color with ribs on it if i remember correctly. They also have some hard black ones) Really trying to get on the water saturday and work 8-8 tomorrow unfortunately. Thoughts on the washers?

 

[Scott Danforth]

Depends on the fiber base. Paper or fiberglass?

 

[Scott Danforth]

The black ones may be acetal (delrin). Those would work if they are acetal

 

[Rob406]

Depends on the fiber base. Paper or fiberglass?

That, i am not sure of. Think they just say “fiber”

 

[Rob406]

The black ones may be acetal (delrin). Those would work if they are acetal

OK to pull the vent plug to replace the washer?

 

[Scott Danforth]

Yes

 

[Rob406]

Yes

Thanks. The factory vent plug was a special screw and was slotted for an o ring. So not sure if i will be able to find a washer. Hoping maybe the dealer has a new screw. Trying to find a p/n now but no luck

 

[dingbat]

Also does it have to be a specific crush washer? Ace hardware has the plastic washers that look exactly the same as the evinrude washers, but they are not sold as a crush washer. Not really sure what they are for.

The OE washers for my Evinrude 200 Ocean Pro are nylon flat washers.

The washers deform when tightened so a new wash is required every time they are removed

 

[Rob406]

The OE washers for my Evinrude 200 Ocean Pro are nylon flat washers.

The washers deform when tightened so a new wash is required every time they are removed

Dingbat according to the above, nylon abosorbs water. I was advised not to use it

 

[dingbat]

Dingbat according to the above, nylon abosorbs water. I was advised not to use it

Obviously different than mine then...

Johnson/Evinrude/OMC New OEM WASHER 0311598, 311598​

 

[Crosbyman]

Idoubt nylon absorb water.... it deforms when crushed the first time and should simply not be reused or flipped over to save a few pennies.


still applies today on modern engines

 

[Scott Danforth]

Idoubt nylon absorb water....

You may want to look that up.