When I opened the upper radiator cap to drain the coolant earlier, a constant trickle of coolant came out of it.

The bike was stone cold (it hasn't been started for at least a couple of days).

Would it be because I had the bike on the Abba stand, and the overflow reservoir might have been higher than the rad cap?

Answered your own question

I always undo the coolant drain bolt first, then undo the rad cap, no leaky leaky down the top rad that way

bikemonkey wrote:Answered your own question

I always undo the coolant drain bolt first, then undo the rad cap, no leaky leaky down the top rad that way

Phew.

I did undo the coolant drain bolt, but nothing came out until I'd pretty much taken the cap completely off the rad. Half a turn my arse - Haynes!

Might have helped if the bike was over on the sidestand instead of up on the Abba stand though.

There are two drain bolts under the front downpipes too.

I always take time to flush the system (hose pipe into it) with all the bolts out just incase and crap has built up in the system.

If your coolant is changed before its no good yuo shouldnt be getting crap though

My coolant looked pretty clean, but I do intend to give it a proper flush, once I've put the top rad back on, after checking the valve clearances. The trouble is I can see that my OCD may spread to the bottom rad while the system's empty... At some point I want to drop the oil so I can check the water pump too. I'm going to be busy...

The Haynes book of lies mentions a coolant system flush - any recommendations on one to use, or just use plain water, as there wasn't much gunk in there anyway?

If your coolant is pretty clean and the bike isn't running hot, I'd just flush everything out with water. Maybe run it up to temp with water then drop it when it has cooled again if you want to give it a good swilling out. I used the obligatory Holt's Radflush the last time I did the coolant, and I discovered that my water pump seal was made of crap that had come out of the cooling system as when the Radflush flushed the crap out, the think leaked... lol

Ok - think I'll stick to water for now then.

Thanks.