Johnson vs Evenrude fuel line connection

[maverickrv]

Im confused regarding the fuel line connections on a Johnson 18hp engine.

The attached pictures show my 40hp 'rude with the pointed connector for the clip and the fuel line.

The Johnson 18hp connector in the picture has 2 connectors, one marked air, the other marked fuel, and then the pointed connector for the clip.

I have not been able to find a fuel connector that would fit the Johnson 18hp yet I have heard they are the same engines, yet you can see they are different.

Can anyone explain what I am missing?

Also what would a proper fuel/oil mixture be to start with for a Johnson 18hp from the late '60's

Sorry for the dumb questions, but I just dont understand engines very well.

Thank you in advance.

 

[petryshyn]

Re: Johnson vs Evenrude fuel line connection

By the connectors, they are not the same engine. The 18hp uses a pressurized tank, and the other engine has an onboard fuel pump system.

 

[a70eliminator]

Re: Johnson vs Evenrude fuel line connection

Your 18hp utilizes a return line and a pressurized tank, the fittings will not interchange with 40hp neither will the fuel tank. Not sure about mix, I was thinking 50:1 but can't be sure.

 

[samo_ott]

Re: Johnson vs Evenrude fuel line connection

Correct. The 18 is a late 50's 18hp as can be seen by the burgandy color. It requires 24:1 mixture and a pressurized (dual line) fuel tank. The dual line connectors are expensive to buy on their own so try to get a tank, hose and connector together. The other option is to mount a fuel pump on the 18 via conversion and to use a single line tank like the 40hp.

 

[tashasdaddy]

Re: Johnson vs Evenrude fuel line connection

to explain the difference the 40 has the single line, because the motor has a fuel pump to suck gas from the fuel tank.

the 18 does not have a fuel pump. it has the 2 line system, one is the fuel line into the motor, the other is an air pressure line, them motor, create air pressure on the tank, and forces fuel to the motor. requires a special tank and fittings.

like this. http://cgi.ebay.com/ebaymotors/JOHN...9279051QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear