I'm very grateful for your continued interest, but I suspect you're viewing the problem on my VFR through the lens of similar (but not the same) issues that you've experienced with your SV650.
My problem is that I get a steady drip, drip, drip of petrol through the overflow pipe, but only when I've brimmed the tank or not far off (I don't know exactly at what point the dripping stops but it seems about when the tank is three quarters full). So the problem definitely involves the internal overflow pipe, but it's not that it's blocked (otherwise I wouldn't get the drip, drip, drip) but that there's a small hole or split in the internal pipe that allows fuel in the tank to make its way out of the overflow pipe when the tank is full(ish).
I've siphoned most of the fuel out of the tank and it's off the bike (it's actually sat on a pillow on a chair in the garage in France) as I also need to have a look at the carbs (when I CBA). I've attached a short length of braided fuel hose to the drain spigot underneath the tank and then jammed an M8 cap head bolt in the other end secured by a hose clamp as a temporary measure to stop the bloody thing from dripping.
I'd filled the tank prior to getting on the ferry, so it was dripping when I left it to go to my cabin, and it was still dripping six hours later when I came back to the bike. Some kind soul had organised a bucket so the fuel didn't drip on the deck, and there was probably about a quarter of a litre in the bucket. So off I rode, bike dripping fuel intermittently until the fuel level dropped below where the hole/split was in the internal pipe.
So as I don't wish to cause a major international fire incident I've capped it off in the best way I can and it will become Future Mango's problem.
Or somebody else's problem if I sell the bike (as I'm seriously thinking of doing).
