1953 Evinrude 15 hp Fuel Connectors

[Adam Fraser]

I have the motor in the subject heading and am trying to figure out a way to get fuel to the engine. I have the original tank but it isnt in any shape for use, I also have a new marine tank with just a single fitting on it (2 lug, fuel and lock).<br /><br />All the fittings i see in the store have one fuel and one locking lug.<br /><br />The fittings on my boat have a fuel, air and locking lug. With three spots.<br /><br />Are there any sort of adaptors that could make this new tank work for me or do I need to find a different tank.<br /><br />Also, if someone could explain the basics of this fuel delivery system it would be greatly appreciated.. I am a licensed motorcycle mechanic so I have an understanding of the carburetor, linkages etc. but have never dealt with marine fuel systems.

 

[Paul Moir]

Re: 1953 Evinrude 15 hp Fuel Connectors

The fuel system on early Evinrudes works by pressurising the fuel tank with air. The pressurized air in the fuel tank then pushes fuel up to the engine. The compressed air comes from the crankcase compression pulses, which is fed through a check valve, and down to the tank through a double-hose line.<br />Modern outboards use a fuel pump and a single line, unpressurized tank. The system is primed by the little hand pump in the fuel line called the primer bulb. When the engine is started, pressure pulses from the crankcase operate on a diaphram type pump similair to a mechanical automotive fuel pump, but minus the mechanical linkage to the cam.<br />There's two solutions to your problem. The easiest and probably least expensive solution is to order a used pressure tank and line from Ebay. They go for around $50 depending on condition. Search for 'pressure tank'. The other solution is to convert the outboard over to a modern outboard type fuel pump, which involves a little mechanical work to mount the pump. Normally, people use one of the two bypass covers which cover the intake side of one cylinder.<br /><br />Hope this explains it!<br /> Exploded view of pressure tank.

 

[Chinewalker]

Re: 1953 Evinrude 15 hp Fuel Connectors

Hi Adam,<br /> BEfore stepping into eBay, take a look around your local marinas, as often they'll have a graveyard of sorts where they toss the "old" stuff, though not necessarily the "bad" stuff. You might be able to find a clean tank or two for the scrap value of the tanks. Also, how did you deem your existing tank as no longer usable. If it's rusty, you can coat the inside with any of the tank sealers they use in motorcycles. If the pump mechanism no longer works, then you can rebuild it (see www.vintageoutboard.com for kits). You can clean the insides of the tanks fairly easily, as the top canister comes off allowing you to get your hands inside (as long as you don't have the forearms of an arm wrestler) to scrub it out with steel wool... The o-rings for the connector itself are still available from your local Johnrude dealer.<br /> If it were mine, I'd stick with the pressure tank system, as it's reliable, and less work and cost than converting to a fuel pump...<br />- Scott

 

[rwise]

Re: 1953 Evinrude 15 hp Fuel Connectors

Adam<br />Welcome to the board.<br /><br />for work around at the house, plug the presure line, and use a small electric fuel pump to deliver fuel to the engine with your single line tank.<br /><br />NOTE: this is for testing only and could be hazardous if used on the water. but just to start your engine it works.

 

[Adam Fraser]

Re: 1953 Evinrude 15 hp Fuel Connectors

It sounds like the modern systems use the equivalent of a snowmobile fuel pump. That may be an answer at least for testing at home, before I outlay $$ for a pressure tank.