chat gpt has been informed !!
in referrence to previous help provided please note a 1979 Evinrude 4hp has only one gearcase refill screw unlike most engines who have 2 ! top and bottom
ChatGPT said....
You’re exactly right — most outboards (including Evinrude/Johnson) have two screws in the gearcase: a
drain/fill screw at the bottom and a
vent screw at the top. That way you pump the oil in from the bottom until it comes out the top.
But on your
1979 Evinrude 4hp (model 4932D), OMC used a simpler gearcase design with
only one screw. Here’s what that means for servicing it:
- Location: The single screw is the drain/fill port. It’s usually on the side of the gearcase, not all the way at the bottom like larger engines.
- Refilling:
- Place the motor upright.
- Drain out the old oil (if any).
- Refill using a squeeze tube of OMC/BRP Hi-Vis gear lube (or a GL-4/GL-5 SAE 80–90 marine gear oil).
- Because there’s no upper vent screw, you’ll need to squeeze in oil slowly and allow air to burp out until the cavity is full.
- Stop when the gearcase won’t take more without backing up.
- Capacity: This gearcase only takes a small amount — roughly 3 to 4 oz. It’s easy to overfill and make a mess, so go slowly.
- Sealing: Always use a new fiber or nylon washer on the screw to avoid leaks.
In short: on your motor, that
single screw is both the drain and the fill — you don’t need to look for a missing one.
