Thanks for your comments. Well unclescott58, that's how they are, still racing in this form and although now 68, I've driven some of these about 5 years ago, on an indoor track. Yes mine had the fuel tank on the left with the engine on the right and when you get up the next day you have a large size bruise under your left arm/elbow where the tank bounced up and down on the concrete surface. And yes the right arm, right side was very warm. I did circuit marshalling at Silverstone Circuit about 5 miles away for nearly 30 years, and whilst there the world championship of karts came to us each year. A friend of the family who has lived in the USA for some years now, had a 250cc watercooled kart with a fully faired body, and coming through the start/finish straight with others of the same were topping 150 mph, in the top class karts! All the juniors here start at 5 or 6 years old with a 50cc engine looking identical to this, and through the age groups go up to 175cc (I think) which was the karts Hamilton and Rosberg (F1 drivers now) raced at 10 years old. Fantastic sport!