Forums General Discussion Fuel tank sender help

Tagged: 

This topic contains 3 replies, has 3 voices, and was last updated by  unabated 1 month ago.

  • Author
    Posts
  • #224557

    Rich Harris
    Participant

    My boat’s fuel sender hasn’t worked since we bought it earlier this year. I pulled the old one and it because there is nothing more than a stripped sender plate with no mechanism inside the tank. (I did check, the rest of it is not inside the tank.)
    I didn’t want yet another electrical circuit so I bought a Moeller mechanical gauge that should be a drop in replacement. Not so fast though. I do have a 5 hole bolt pattern on the tank that is laid out with the SAE style pattern with one exception. The diameter of the bolt pattern is larger than the 2 1/8″ diameter pattern by about an 1/8″ which makes it so I can’t bolt it down using all five holes. Has anyone encountered this? If so, what did you do to rectify it? I’m thinking of one of two solutions. Ream out the holes in the gauge or make an adapter plate to go between the gauge and the tank.
    Any thoughts? Is this possibly metric or some special layout? I know I’m grabbing at straws since my tank is aftermarket probably made in Panama. One other clue, the original gauge holes are factory made not custom drilled.
    Thanks,
    Rich

  • #224558

    RichCarter
    Participant

    My boat, and I think all 424s, was built with a mechanical fuel gauge. This was, IMHO, a cheap solution. I had to kneel down with a flash-light to view the gauge. Not practical when filling the tank and not something I enjoyed doing under any circumstances. When I repowered, I replaced my tank and had the tank company install an electric sender. They of course cut the tank holes to match their sender. I don’t suggest reinstalling a mechanical sender.

    No matter which sender you install, beware of the position the sender is installed in. There’s a baffle in the tank. If you install it improperly, the sender arm will hit the baffle and not register properly. You can get a sender that doesn’t have an arm. Instead, it travels on a pair of vertical rails. You must get the sender length correct for this to work but it avoids the problem of hitting the baffles. That’s what I had done. I think the rail length can be shortened by cutting it.

    If it were me, I’d toss the mechanical gauge you bought and put in an electric one.
    If you chose to install the mechanical sensor you bought, I’d recommend drilling the sender holes to mach what you have. Rotate it so the gauge arm doesn’t hit the baffle.

    Rich

  • #224559

    unabated
    Participant

    Save yourself a whole lot of hassle. Scrap the fuel sender. The senders are pretty much linear and the tanks have an odd shape so it’s never going to be accurate.
    Use this no fail method.
    Fill the tank. Note engine hours.
    Engine uses .75 gallons per hour if you keep it below 2200 rpm. More rpms more fuel. Look up fuel to rpm curve for your engine mine is a w58.
    That gives you a 25 percent safety factor. I’ve used this method throughout the Caribbean and Bahamas and works perfectly. Usually right on the money.
    Alan
    Unabated

  • #224560

    unabated
    Participant

    Save yourself a whole lot of hassle. Scrap the fuel sender. The senders are pretty much linear and the tanks have an odd shape so it’s never going to be accurate.
    Use this no fail method.
    Fill the tank. Note engine hours.
    Engine uses .75 gallons per hour if you keep it below 2200 rpm. More rpms more fuel. Look up fuel to rpm curve for your engine mine is a w58.
    That gives you a 25 percent safety factor. I’ve used this method throughout the Caribbean and Bahamas and works perfectly. Usually right on the money.
    Alan
    Unabated

You must be logged in to reply to this topic.