Having spent too much time too many times and too much money with this starting problem, which I nailed down to a tendency of the bike to flood if anything at all infers with the start, which should be idiot proof and not require a check list. Yamaha are talking of an ECU fix. Well they ain’t told me about it, probably because of the money I’ve spent. I’m on the phone tomorrow. By the way, you might have noticed that the cylinder head cover of the S10 has a rim around it’s edge, well this catches and pools water, which manages to get down the spark plug recesses when it’s guided down there by the fork yoke and bypasses the front of the tank. The result you can see in the pictures (the bad spark plug that’s been sitting in water) was on the side stand side. She’s not neglected and not left out often. But after an overnight stop and misty morning with plugs with 4000 miles+, start up becomes an issue. Also these plugs were fitted by the dealer and only (the bad one) was seated properly.