Universal M-25 Diesel "Drain" plug on Exhaust Manifold??

[sinnerman]

I have a 1984 Catalina 30 Mk 1 with a Universal M-25 (not XP ) diesel.

There is drain plug on the aft end of the exhaust manifold / coolant reservoir.

Is this plug to:

-Drain the coolant from the reservoir - or -

-Drain raw water trapped in the exhaust riser at the manifold exit?

See pics.

Thanks in advance.

Cheers

[Jim Cate]

Almost certainly a drain for the coolant. But just crack it a bit and see what comes out... if it is green that will tell you something!

Jim