Uploaded July 2025 | Updated September 2026, 2 days ago
The first few miles on the new carb have been all about finding the best jets for regular riding, but now it's time to start trying jets that will suit higher rpms. I've settled on a main jet that is a similar size to the Amal 250, which gave a similar combustion chamber condition, but the flame path is seriously restricted by the weird spark plug location, and also the high dome to the piston. This little blast has shown the spark plug heat range to be not quite right, so I have a couple of colder plugs to try at the same time.
The first few miles on the new carb have been all about finding the best jets for regular riding, but now it's time to start trying jets that will suit higher rpms. I've settled on a main jet that is a similar size to the Amal 250, which gave a similar combustion chamber condition, but the flame path is seriously restricted by the weird spark plug location, and also the high dome to the piston. This little blast has shown the spark plug heat range to be not quite right, so I have a couple of colder plugs to try at the same time.
