Changing Gear Oil when No Upper Vent

[IBashaw]

Hi Folks <br />I have a 1975ish 4Hp Evinrude that is overdue for a gear oil change. How do you know when the unit is full when you don't have the usual / typical upper vent hole. I do not see anything that looks like it would be a vent hole screw...nothing. Help!!

 

[marinemech1]

Re: Changing Gear Oil when No Upper Vent

i can't acess parts diagram but there should be a vent usually near anti cavition plate

 

[Xcusme]

Re: Changing Gear Oil when No Upper Vent

LordSheffield , Welcome to iboats ! <br /><br />You don't have a vent screw on your motor. With motor in an upright position, remove the lower unit drain screw. Lube will drain out.<br />Lay motor on it's side and refill lower unit with lube slightly below drain opening. Replace drain plug and washer to prevent water intrusion into lower unit.

 

[IBashaw]

Re: Changing Gear Oil when No Upper Vent

Originally posted by Xcusme:<br /> LordSheffield , Welcome to iboats ! <br /><br />You don't have a vent screw on your motor. With motor in an upright position, remove the lower unit drain screw. Lube will drain out.<br />Lay motor on it's side and refill lower unit with lube slightly below drain opening. Replace drain plug and washer to prevent water intrusion into lower unit.

 

[IBashaw]

Re: Changing Gear Oil when No Upper Vent

... thanks tons. I was sure that I was not missing it, thanks for confirming and also for the guidance. <br />Any reason why not to use Yamaha gear fluid (which I use in my 2004 15Hp Yamaha outboard) in my older Evrinrude??<br /><br />Ian

 

[Xcusme]

Re: Changing Gear Oil when No Upper Vent

The Yamaha gear fluid should work a treat.