Why Not Use Automotive Parts on My Boat Engine?

Recently I was asked the question “Why not use automotive parts? You have seen the big difference in the cost or “Marine Parts” as opposed to “Automotive Parts”. You have also said that the engines are the same so why not?”

There is a difference. A big difference! Autos are designed so that the engine is sitting over the ground and if there is an occasional drip of a little gas, it just falls on the ground and evaporates. BOATS HAVE BILGES AND THEY ARE ENCLOSED. Those little drops of gas evaporate but stay there and become a very powerful bomb with an ignition source.

Marine Alternators have contacts that are not exposed. Marine Distributors have ignition protection and flame arrestors. Marine Starters and Generators are completely sealed. Marine Starter Solenoids do not have the vent that auto solenoids do. Marine Carburetors vent any overflow back to the throat so the engine burns it, vs. venting to the outside as in all automotive carburetors. Marine Fuel Pumps will not allow fuel out of the diaphragm area if there is a leak, vs. a vent hole to the outside as in automotive fuel pumps.

These requirements are enumerated in the 33 CFR 183.410(a) http://uscgboating.org/recalls/pdfs/BSC69.pdf if you would like further information, or ask your Vessel Examiner during your next Vessel Safety Check which can be obtained by calling me

Categories: Seamanship