Studying my new yanmar y2m15 , few questions

[maury]

I bought the sailboat used with new never used engine and am navigating splash and breakin prep.

Manual talks about with illustrations coolant drain plug and coolant drain cock. What is the difference between them in terms of function.

[Adelie]

Don’t know for sure but my guess is the drain cock would conveniently allow most coolant to drain out and the drain plug would inconveniently allow all the coolant to drain almost to the last drop.

Drain is probably on the bottom of the motor and the cock is higher and has better access.

[skipperpete]

My service manual is an old one and it only has an image of the 3ym but maybe this will be of some use, 4 drain points, 2 for coolant and 2 for raw water. [ATTACH]

[maury]

Ah, maybe its that simple.

https://www.yanmar.com/marine/wp-con...28_2019.12.pdf