Hi,
I have recently refurbished the carbon brushes on my 250SE fuel pump. It is the tall type of pump. In the process of dismantling the pump, I've lost the Woodruff key that stops the impellor from spinning on the shaft.
The specifications state the key is 2x1.5x1.5mm. I have tried making one from key steel but it seems too small and falls out.
I would appreciate if someone could offer advice on why this is not working or where I could purchase the correct key.

Thanks
Alex