Racor in fact makes a diesel
fuel pump that is off the shelf and about $80US when i bought one for my
yanmar 2GM20. the info you need is what is the required maximum gallon per hour diesel
fuel flow rate for your 40 HP isuzu
engine, should be able to find that from isuzu on the
internet or in yr engine manual.. the RACOR diesel pump had an inlet and an out let fuel hose , clearly marked and also the
electrical connections (also clearly marked. ) many auto part stores also carry diesel fuel pumps but be careful on the flow rates, some of the big diesel SUV's running 300 hp will have diesel pumps which are too powerful for your system. when swapping out the fuel pumps, have a helper with an old rag ready to catch the drips. quickly disconnect the fuel hose and hold it high in the air to keep fuel from leaking out and getting that diesel fuel in yr
bilge. i usually grab some disposable diapers from
family members and blanket the engine compartment with them to avoid a messy spill. check your fuel hose diameters and make sure the new diesel fuel pump will accomodate the
ports. after installing the new pump, you should bleed your system to get the air out of the pump at what ever bleed screw is located after the
electric pump and before the secondary 'fine' filter on the engine.