E-Bro&reg; Black Rubber Fuel Transfer Vacuum Fuel Line Hand Primer Pump Bulb Type For Marine Boat Diesel Accessories (8mm) The pump is temperature resistant up to 95  C. Hand bulb primer to suit petrol of diesel comes with a one way valve installed to help quickly prime the fuel system. Frequently used as a hand pump in boats for fuel supply to the out-board engine. This fuel primer bulb is ideal for vehicles without ESP-priming, using 1 or 2-tank systems, as well as for the transfer of vegetable oil, diesel, it is most commonly used on outboard or inboard boat engines.