Well, I've recently been away on the EMM 2026 trip with a few pals from the UK and on the day we arrived at our EMM hotel location at Besse et Sainte Anastaise, Auverne, Rhone, on the 22nd June, we stopped for fuel at a local fuel station. When I opened the fuel filler cap to re-fuel, my goodness the pressure release added together with fuel spray over the screen area, caused me rather a lot of shock I have to admit, instantly necessitating pretty prompt closure of the cap! I then released the fuel cap very slowly indeed, allowing the tank pressure to dissipate gradually for about 10-15 seconds and then was able to fill the tank again. The tank expansion was quite extreme, causing the tank cover to crack at the top cover fixing mounts, as well as making the telephone pocket expand likewise and totally change shape. I managed to 'deal-with' the issue, after some advice, which continued throughout the remainder of the trip, having began in France on the 20th June and ended when back in the UK on the 29th June. No apparent issues with the tank for the 1st 2 days or so. I released tank pressure every time I stopped the bike for a break or to re-fuel, meaning all in all circa 40-50 occasions. This approach seemed to keep things under control to a greater extent and certainly reduced my initial concerns. The bike didn't falter in any other way at all and as we headed north towards Calais via Luxembourg & Belgium, where the daily temperatures reduced to about 28-30C, the tank pressure problem, seemed to disappear altogether. Temperatures throughout France during our trip were frequently in the 36-40C area and my bike certainly seemed to run very hot, which I do appreciate is a V4 trait. We did a similar trip last year, in similar temperatures, with no issue whatsoever. However, this time, I did see the temperature head to 108C on the bike and on at least 2 separate occasions the fans cut out at 104C, also rather strange as they are set, I believe, to cut out at 99-100C. I did speak with a very helpful guy called Barry @ Riders, Bridgwater, on the 24th June, who indicated he hadn't heard of this before and that on looking online, found that reactivity of E10 fuel in high temperatures was a known issue, suggesting I ought to opt for E5 for the remainder of the trip. I did try to do this, however, found that not all fuel stations had this available. I would say I managed to utilise E5 for about 60% of refills after this issue first came to light, but that it seemed to make no discernible difference at all. The bike is booked into Riders for detailed exaamination on the 28th July and still has 80% of its final year warrranty. I'm anticipating that whatever the issue might be, this will be fully covered by warranty, including the tank cover damage caused by the significant tank expansion. If anyone has any useful thoughts about this problem, they may well be helpful.
Mine pressurised once, it was from over filling and blocking stupid charcoal canister thing, I just got a Y connector, cut the pipe and joined it into the other overflow pipe that goes to the ground, no issues since, even if I over-fill.
