Water drains and parts NLA

Hi Folks.
Question for the experienced.
Where to completely drain cooling system as I have pulled the drain bolt out of the pump and still water in block between heads?
Seal that attaches Chrome pipe from water pump to fitting bolted to block.
This 91315MB6003 O ring is NLA or should I order 91315MB600 instead?
Is this something special or a common o’ring?

There are two drain bolts on the front face of the front cylinders under the heads. That’ll release some more coolant.


Cheers DonR
A nice brown colour
Can you answer the other question as I worked out it is a13mm Oring?

Don’t know. We went a different direction.

Cheers Don.
Going to leave well alone and fix the immediate leak.
Will see how the rest of the bike goes and come back to this.
I like your idea and will consider your idea.

I can’t remember the size but I used standard O-rings and it’s been fine. I can’t recall the sizes but as long as there’s some adequate squish, it will be fine. I might’ve even put in a second one for good measure so there are two at each end, back to back.