Re: Mercury 1500xs gear oil change
That motor is pretty rare and likely worth some $$ or is it EE?
There is a drain plug (stainless slotted screw) under the "bullet" part of the gearcase in the front. Loosen it with an impact driver and remove it. There is a second plug above the antiventilation plate on the side of the motor. Loosen as before and remove. The gear oil will drain out the bottom. let it all drip out and refill with any marine gear oil for mechanical shift motors. It will take 25+ oz, so buy a quart (liter).
Sorry, don't rermeber if you Scots are metric or not......