I've got a YS 140 DZ that is not idling right. It runs fine above idle, but when you go to idle, the rpm's go up and down quite a bit (surging), and the engine eventually dies suddenly. I've tried a new glow plug (OS "F" type) with the same results. I've also tried adjusting the low speed regulator at least a full turn each way with no change.
My next step is to check all my fuel lines for holes/splits. Other than that, I'm at a loss.

Have any of you experienced a similar problem, or does anyone have any other ideas as to what my problem might be?

Thanks, Jim