Marlin aux fuel fill

Buffalo Btms

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2018 Marlin: Finding it difficult to fill the aux (rear) fuel tank. Rate that it accepts fuel is much less than the first auto-notch on the handle. If more than that, it bubbles up / shuts off. Initial guess is vent is restricted, or fill neck was kinked during install.

Didn't have time to track it down this weekend. Short of providing some compressed air to check or force it, where is the vent hose / outlet typically routed?
 

ltid8732

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I have a 98 marlin and it does the same when tank is extremely empty. The fuel tank vents in the filler assembly and it vents causing the fuel to bubble, do not think you will find any obstructions
 

Harpoon

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sounds like a kinked vent line. that's a new boat, i'd tell the dealer
 

DennisG01

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There's another variable here - newish boats have EPA restrictions. Similar to cars, the fuel systems must now include a vapor recovery system. In the end, though, I think the answer is the same - talk to your dealer. Another possibility is that the vent line has a slight low spot and it has fuel in that low spot (another type of restriction). Still another... if the fill line is run too horizontally or has a slight low spot in it, it doesn't "empty" as quick as it should.
 

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There's another variable here - newish boats have EPA restrictions. Similar to cars, the fuel systems must now include a vapor recovery system. In the end, though, I think the answer is the same - talk to your dealer. Another possibility is that the vent line has a slight low spot and it has fuel in that low spot (another type of restriction). Still another... if the fill line is run too horizontally or has a slight low spot in it, it doesn't "empty" as quick as it should.


What he said....
 

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Had the same problem this past weekend in my 2004 Marlin. Filled and topped off the main tank nicely. Went to fill the aux tank and based on my calculations it should have taken at least 70 gallons. I could only get 10 gallons in. It backed up and gas came out the fill spout a few times, nothing out of the vent. I gave up thinking I miscalculated how much was needed in the tank. I later looked at my notes and did some further calculations and the aux tank should require another 60 - 70 gallons to be full. My suspicion is that in filling the main tank, I overfilled and gas got into the vent line. Then the aux tank would not easily take additional gas. After burning some fuel out of the main tank, I will retry to refill the aux tank first. Any thoughts or similar experiences?
 

SkunkBoat

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each tank has its own vent hose.

If its a vent problem then the gas in the fill hose will eventually gurgle into the tank. You would be able to fill slowly by depressing the pump nozzle very lightly.

I would first inspect as much of the fuel line as you can for kinks.

Next time filling, the previous gas should have made it into the tank so if it overflows too soon, wait and listen for it gurgling into the tank.

What does the fuel gauge read?