2004 fs650 loosing coolant?

Morning boys and girls I'm looking for some advice...

My fs650 appears to be loosing coolant somehow and it's got me a bit stumped !

I fill the rad completely full to the point of overflowing (it drops a little out the overflow ) and then go for a say a 10 minute gentle ride and then when I check the coolant again there is none visible in the rad?

The oil level hasn't risen and it's oil is not contaminated, I'm not getting any white smoke to say it's being burnt off in the cylinder and I have no water leak? So I have absolutely no idea where it's going UNLESS it's not supposed to be visible in the rad when looking through the fill hole?

I wouldn't say the engine feels like it's cooking nor can I hear it boiling over or the pipes expanding to show it's pressurising and there is no smell of fuel/soot in the rad it's got me stumped!

This is my first berg and I'm still getting used to it so please go gentle on me...

Many thanks

Nope those seals and gaskets was replaced a while back so no issues there at all

i dont know thats the problem ! ive been filling it to just below the over flow and then ride say 5 miles and then stop and check water level and i cant see any water in the rad?

are you supposed to be able to see water in the rad or should it sit just below the top of the fins out of sight ? i cant see it leaking anywhere so its got me stumped!

should add that ive also bled it up with the bolt on the side of the head so dont think its an air lock or anything like that