I have a 1987 Elan 250 with issues. Somewhere it is picking up air in the fuel line. You can see it from where it tees off up to the primer and down to the carb again. When running you can see that the fuel and air to and from the primer continues to flow. Because of this I cannot get the motor to idle. I have replaced all the fuel line, put a new kit in the fuel pump, and replaced the rubber boot between the carb and engine.. As I remember, as it has been since last year that I enjoyed the machine, the fuel should not be flowing in the primer tubes when the engine is rinning. My next move is to buy new a primer, complete fuel pump, the intank filter and the rubber grommet on top of the tank. Just wondering if anyone has ever had a similar problem.