Before Posting, Please Read Our Posting Guidelines Below.
1. Use the full 4 digit year for everything you are asking your question about. Example: 1962, 1988, 2000, 2011 2. Include the correct name of your Whaler model. Example: Montauk 17, Montauk 170, Outrage 26, Outrage 260 3. Include the length when necessary. Example: 16, 17, 18, 20, 22 4. Do not post your email address anywhere on this site as it is already in your user profile.
Fuel Demand Valve Montauk 170 No longer necessary??
Hi, this topic has been debated thoroughly, but many of the threads date back 10 years ago. Thanks for your help.
Summary: A west marine sales guy is claiming fuel demand valves aren't necessary anymore because companies like Moeller have redesigned their tanks making the fuel demand valve obsolete. Is this true?
Details: I just replaced the two Moeller 6gal portable tanks on my 2014 Montauk 170. I have the original 2014 90hp EFI Mercury. The original fuel tanks were faded and beginning to crack. The sales guy at West Marine was adamant that the fuel demand valve was no longer necessary because Moeller has changed the design of their tanks. I haven't seen any evidence of this in the marketing or enclosed directions. To his point, the tanks came with a hose assembly with priming bulb and quick connects, but no fuel demand valve (see attached photo of new tank) As further evidence, the sales guy pointed to an "old style" hose kit that included the fuel demand valve and said that the single remaining package was their last and they don't plan to stock it anymore. He was adamant that he was right, but couldn't offer an explanation other than "you just don't need it anymore." Is deleting the fuel demand valve fact or fiction? I've seen questions around the CARB tanks and new EPA rules debated heatedly, but am just looking for a practical explanation and/or confirmation that the valves are no longer necessary.
My original fuel line set up has the following set up (see attached photos)
Tank Side: Tank--->18"hose---->Fuel Demand Valve---->6"hose---->Quick Connect Coupler
Engine Side: Quick Connect Coupler----->fuel hose direct to Engine via floor tunnel.
Observations/questions
1) There is a fuel demand valve connected to each tank along with 18" of hose. If the valve is necessary, is there a reason there needs to be one per tank that stays with each tank when connected or disconnected? I'd prefer a simple quick connect fitting mounted directly to the tank so that there aren't hoses flopping around during transport.
2) There is currently no primer bulb. Do I need one? A motörhead friend of mine with no boat experience said, probably not because of the EFI fuel pumps.
From Attwood, a manufacturer of this type of product:
The integrated fuel demand valve, used in conjunction with integrated fuel systems, is for below deck use, eliminates pressurized fuel from reaching fuel distribution lines and your engine and ensures that fuel is provided to the engine on demand rather than as a result of pressure in the tank.
If you have a Moeller fuel cap that has a manual or automatic vent, a fuel demand valve is NOT necessary.
I have run 3 boats with on-deck and below deck tanks over 20 years and never needed one of those.
You will want a primer bulb inline because at some point you will loose prime doing maintenance, replacing a hose etc. Recommend OEM branded primer bulbs. The aftermarket brands have short lives.
Your setup sounds extra complicated.
When I run one or more portable tanks I have one fuel line from the engine, up through the tunnel and the primer bulb installed 6" from the tank end with a quick disconnect. Each tank has a quick disconnect.
Some owners hate the new EPA compliant fuel caps (too tall) and replace them with an old style cap with a manual vent screw.
