That's a clutchless 2 stroke engine, being rental probably TKM, and long geared. It may have been club 100 (which is a rental league that goes up and own the country) or Buckmore may have experimented with a fleet of 2 stroke karts. In any case, I for one am not driving to kent to race the track.
It may well be owned by Jonny Herbert, but that doesn't make it a great track... What that makes it is a popular one where, as an owner driver, the circuit completely disregarded it's customers.
I turned up to practice for an endurance race, paid my daily fees (slightly more expensive than some other tracks for a days open practice) and then got told I could only go out only at certain times of the day, and for a grand total of 4 x 10 lap runs ... barely enough to get heat into an endurance setup, and a complete rip off for 40 laps driving.
I have never returned to Buckmore since, and I wont...