[neolith2099]

This conversion could also utilize the later fuel pump of the 6hp up, and newer motors if the mounting base was altered to the newer pump. By this what I mean is that if you are not as lucky as I was in finding this unit, then take the original sideplate, build it up with J_B Weld epoxy, file a flat to mount the new pump. Then drill and tap mounting holes for the new fuel pump, drill a vacuum hole to match the center hole of the fuel pump in this altered sideplate. The vacuum hole does not need to be in any exact location, just so it goes thru the sideplate. [links]

[greene63]

The new tanks have a vacuum valve in the tank so manual venting is not required. However if the tank is used basically as a spare/emergency tank and in warm weather the fuel expands, this new valve system only opens when the motor sucks a vacuum and does not allow internal pressure to escape. What happens then is that the pressure builds to where it then blows fuel out around the quick coupler on the quick disconnect coupler O-Ring. [links]

[wlisabethfitzgeraldv]

Portable boat fuel tanks sold in the USA since 01/01/2012 must be the EPA-mandated "self-venting" design instead of the previous version with a screw-type vent in the cap.

[riX]

For a very in formational illustrated article in doing this on a 5.5hp Johnson CLICK HERE However different size motors may vary from this article. more

[blurden]

Thanks for the input. I actually have two 6 gallon plastic tanks in my boat. My original thought to use both for weekend trips or long runs with either motor. I could run one for each outboard though. 50:1 for the Mariner and 24:1 for the '57 Johnson.
Maybe I went the harder route on doing the conversion. It was actually a pretty simple mod. The nice thing about it is that I can swap motors and use the same fuel line for either! [links]

[joshuaissac]

Re: converting older dual fuel lines to a single fuel line [links]

[specious]

Re: converting older dual fuel lines to a single fuel line

[artdegree12]

HI bplayer. Welcome to iboats. Here are some great links that can walk you through the entire conversion process as well as a few general maintenance links. more

[Guillermo]

Re: converting older dual fuel lines to a single fuel line [links]

[goodhope]

For the record, your 18hp is all needle / roller bearings, basically same as the the newer 50:1 models. Y'all guys can fight it out over the fuel mix question. here

[sherrymade356]

1 - If no fuel is being pumped from the tank when you're pressing the plunger, you'll need to dismantle the tank to find out why
2 - Air pressure from the engine. You'll need to disconnect the air hose when the engine's running.
3 - The "O" Rings can be replaced. no need to replace the springs unless they're broke.
4 - That's up to you. check that gas flows when you pump the plunger etc.
5 - Some engines can be converted to a fuel pump. some can't. Some other member will need to answer that question. here

[Veltas]

The cap on the pressure tank must be tight. The plunger must be pressed until it is hard (carbs etc full) with the fuel connector attached to the engine. Even when all is well, it takes a few false starts to get pressurized air into the tank unless it is absolutely full. You don't say how long this engine has been sitting. how long?

[hubdawg]

Bottom line. If by carefully depressing the bra$ fuel valve in the fuel connector and pumping the tank plunger, no fuel is pumped out the connector, dis***embly of the tank is a must to find the cause. here

[xswqaazz]

here

[dorianm421]

more

[gilbertj0hn]

Hi – My first post here, as a guest.
I’m presently working on the motor in the subject line – Going through the water pump, carburetor rebuild, and ignition tune up that’s usually / always needed to try to bring an old motor like this back into service. Also doing a fuel pump conversion, as it didn’t come with a tank. I think the motor is basically OK, but it’s been parked a very long time

[SiBorg]

Joining AOMCI has priviledges 🙂 [links]

[cuu508]

Just speculation, but the 7 1/2 was the highest hp motor that had plain bearings so I wonder if they were concerned about bearing load(?) [links]