I was riding up Oxford Street in 5th doing about 6K revs when the engine revs start dipping, I drop a gear and still the engine revs keep dipping. This happens as I drop through the gears until the bike eventually stalls. I started again and off I go but I still get the engine revs dropping off until I got home about 5 mins ago. I have never run out of petrol but I am assuming thats the problem. I open the tank and shine a tourch into the tank, and I have about 4cms of petrol in the tank. Is that the reserve? I always thought that the reserve was somewhere else, but is it just the lower part of the main tank? Is that what I can expect when I run out of petrol?