Evinrude big twin 40

[Open Water]

I have a 1967 Evinrude 40 hp big twin electric shift. My issue is with milky lower unit lube. Had it air pressure tested and held for a full day. Fella told me it looked like the seal had been changed. I’ve changed lube a few times this summer, it’s worse after I run it in higher rpm’s. To me two things are different from pressure testing or in the lake. Drain and vent plugs and RPM

 

[jimmbo]

Welcome to iboats

Likely the Seal under the Water Pump.

Have you tried pulling a Vacuum on the Case?

Looking at the Pic, the Boat looks like it is nice Condition

FYI, Your motor was called 'LARK'. 'Big Twin' would have been used for the Mechanical Shift models

 

[racerone]

Are you checking gear oil 1 hr after your trip or 3 days after your trip ?

 

[Open Water]

Are you checking gear oil 1 hr after your trip or 3 days after your trip ?

Yes right away

 

[Open Water]

I have a 1967 Evinrude 40 hp big twin electric shift. My issue is with milky lower unit lube. Had it air pressure tested and held for a full day. Fella told me it looked like the seal had been changed. I’ve changed lube a few times this summer, it’s worse after I run it in higher rpm’s. To me two things are different from pressure testing or in the lake. Drain and vent plugs and RPM

Thanks I’ve done a lot. No vacuum yet, I think I’ll just replace the seals. Would you think the screw washers are bad. I’ll change those 1st.

 

[racerone]

Could be tiny air bubbles.----Let sit for 3 days and check.

 

[Open Water]

Could be tiny air bubbles.----Let sit for 3 days and check.

Don’t think so, I save each drain store in clear bottles. Some have been still for over a month. A thin layer of clean oil near the top.

 

[Open Water]

Thanks I’ve done a lot. No vacuum yet, I think I’ll just replace the seals. Would you think the screw washers are bad. I’ll change those 1st.

Well all be go to…. It says Lark on the back.

 

[jimmbo]

The Washers on the Screws should be replaced every time the Screws are removed/loosened.

 

[racerone]

Best to look after that electric shift gearcase.-----New seals are cheaper than the springs , clutches and gears.

 

[tphoyt]

Yea unless your a serious time crunch May as well do the seals and be done with it. Then you know everything looks as good as the rest of the boat.

 

[kbait]

Use omc premium blend or older type c in your electric shift gearcase..

 

[airshot]

Very cool looking boat and motor, brings back memories from my youth. Hopefully we will see the boat in action when you get the bugs ironed out !

 

[jimmbo]

As Mentioned about the Gear Lube, but beware that some 3rd Party Oils claim to be Type C, but then go on to say they are NOT Compatible with Electric Shifts