Fuel Line Connector Confusion: Merc v. Johnson

[P51D]

I have a Bayliner Rendezvous with a '91 or '92 Mercury V-6 175 HP 2.5 litre, carburated. The Merc is fed from a built in tank, and the 3/8? fuel line has what I guess is a ?standard? Merc connector at the engine.

As an emergency kicker engine, I have a 9.5 HP Evinrude, 1973 model year. The model number is 9322B. I have 6 gallon portable tank for it. If I remember right, the connectors on both ends of this 3/8? fuel line are identical.

On occasion, I want to run the big Merc from the 6 gallon portable tank, so I want to rig up a hose just for this purpose.

I thought this would be a pretty simple exercise. Find a 3/8? fuel line and primer bulb. Find a Merc fitting for 3/8? line for one end, and a JohnnyRude fitting for the other, pay the man, done.

I went to a big-name, boating chain-store, told them what I was up to, and then we all got confused.

I was told that the fuel line fitting on the engine side was usually different than the tank side (not the case on my existing hose; arrow on the bulb keeps me out of trouble). Of course my new custom hose will have two different fittings by design, but is this usually the case?

They also implied that there were different sized fittings within engine brand. I didn?t know if he meant just fuel line diameter (e.g., 5/16?, 3/8? etc.), or connecter size, or what?

So my questions are these:

1. Is there a special ?Fuel-tank end? fitting, that is different from the ?Engine end? fitting? Or are they interchangeable?

2. Are there different sized fittings within engine brand (e.g., Mercury small, med, large, etc)? I?m not just asking about fuel line size; I?m asking about the physical shape/size/construction of what actually plugs into the engine, and or portable fuel tank.

Thanks

P51D

 

[Chris1956]

Re: Fuel Line Connector Confusion: Merc v. Johnson

P51D, You are essentially correct, the connectors for the older johnson/evinrude motors were the same on both ends. Merc used a female fitting at the motor and a male fitting at the tank. You buy replacement fittings of any type. If you can stand the inconvenience, buy a Merc Female fitting with a hose barb. When you want to use the OMC fuel line and tank, pull off the J/E engine fitting and stick on the merc fitting.

Alternatively, buy a new fuel line of the Johnson/Evinrude type and a Merc engine fitting and install it on the output end.

BTW - I presume the small motor is gas-oil premix, the the large motor is oil injection? When you change over to the small tank, you will be running double oil. It won't hurt anything BTW.

 

[Chris1956]

Re: Fuel Line Connector Confusion: Merc v. Johnson

One more thing. Stick with a 3/8" fuel line and fittings for the Merc. Although your J/E motor may have a smaller fuel line, it is more likely that it is already 3/8"

 

[P51D]

Re: Fuel Line Connector Confusion: Merc v. Johnson

Thanks Chris 1956.

 

[eli_lilly]

Re: Fuel Line Connector Confusion: Merc v. Johnson

To help you from ending up with a kitchen counter full of useless fuel connectors, like me, I'll offer the tip that there are apparently two different Mercury connectors (male/female difference aside). The packaging just said "Mercury".

-E

 

[seahorse5]

Re: Fuel Line Connector Confusion: Merc v. Johnson

.

On occasion, I want to run the big Merc from the 6 gallon portable tank, so I want to rig up a hose just for this purpose.

Just get a male OMC fitting to plug into the existing hose, and the Merc fitting for the other end, with about a 6" piece of hose between them.

One word of caution, 6 gallon tanks are made for midsize enignes and could cause a fuel restriction and possible engine damage if you run the Merc at high speeds with it. Keep the speed to about 1/2 or less to avoid any damage.

 

[Scaaty]

Re: Fuel Line Connector Confusion: Merc v. Johnson

Just put OMC fittings on the tank ends..I run a Merc OB on one of my boats (BIG HP)..Merc Fit motor, omc Male/Female tank fittings...Walmart, under $10...Just switch hoses for what ya wanna run....simple..

 

[P51D]

Re: Fuel Line Connector Confusion: Merc v. Johnson

All - Thanks for the advice. P51D

 

[rdgordon1@cox.net]

Re: Fuel Line Connector Confusion: Merc v. Johnson

Let me try to remember now,the "D" had the full plexiglass canopy,right?
What a sound!!!Ron G

 

[P51D]

Re: Fuel Line Connector Confusion: Merc v. Johnson

Yes, Ron G, the P-51D was the Mustang with the bubble canopy. It's the Mustang that most people envision when they hear the name.

 

[P51D]

Re: Fuel Line Connector Confusion: Merc v. Johnson

OK, I'm most of the way there. I followed Seahorse5's advice, essentially making an adaptor that goes between the Merc engine and the OMC hose. But it leaked where the connector plugs into the engine. AAARRRGGHHH!! The connector SEEMS to fit, but definitely leaks. So I compared the original connector to the new one, and I saw that the original has what looks like a flat rubber gasket/washer that is flush with the "face" of the connector; the "face" being the portion that faces the engine. The new connector face appears to be all plastic with no flush rubber washer.

Searching this site and the web, if a year is mentioned, it seems to say "1993 and newer". Best I can tell, mine is a '91 or a '92 (serial #OD223009). Any advice on where to get the proper connector? A brand and part number would be really welcome at this point.

The one connector that I saw that did show a rubber washer was for a metric sized line, and/or somewhere in the 5/16" size, while I've got 3/8". I may just have to accept the 5/16" barb and let the clamp "take up the slack"? I'm afraid I'm going to end up like Eli Lilly - "with a kitchen counter full of useless fuel connectors". This shouldn't be this hard . . . .

Thanks

P51D