Fuel vent problem - Maxum Boat Owners Club

9Ball · 07-11-2011, 12:34 PM

I have a 92 Maxum 2100SC, every time I fuel I have to keep the flow very slow or fuel will burp out the Fill (not the Vent) and sometimes I can only get 2.5 - 3 gals in the tank even though its 1/4 full. I have checked the vent tube and it is clear from the back to the top of the tank. I am not sure how to check inside the tank. Any help would be appreciated.

ss3964spd · 07-11-2011, 02:42 PM

9B,

If possible, remove the vent hose from the hull fuel fill fitting and use compressed air to blow through the vent hose towards the tank. Even easier, ensure the entire vent hose is free of kinks.

Aside from that you'll have to remove the assembly from the top of the tank to inspect the pick up and vent.

Dan

9Ball · 07-11-2011, 04:15 PM

Quote:

Originally Posted by ss3964spd

9B,

If possible, remove the vent hose from the hull fuel fill fitting and use compressed air to blow through the vent hose towards the tank. Even easier, ensure the entire vent hose is free of kinks.

Aside from that you'll have to remove the assembly from the top of the tank to inspect the pick up and vent.

Dan

The line is clear to the tank, and the fitting.... well it is a 90Deg fitting and is against the bulkhead so I am not sure how to get it out without tearing the boat apart.

ss3964spd · 07-11-2011, 04:39 PM

I wonder if the vent line, while clear, is only partially clear. I wonder, too, if the fill hose may have shifted and now has a section the runs horizontally - maybe even up hill for a stretch, before getting to the tank.

Where does the vent line connect to the tank; at the sending unit ot near the same place as the fill hose?

9Ball · 07-11-2011, 06:15 PM

Right next to the fill line and the supply line to the Engine fuell pump Oh and the sending unit. all the lines and sending unit are on the the top aft section of the tank. I think I am going to reposition the Fuel line and see if that helps.

9Ball · 07-18-2011, 04:01 PM

does anyone know if there is a "Check Valve" in the Vent system?

seapuppy · 07-18-2011, 04:40 PM

shouldn't be a check valve in the vent.....

SP

07-21-2011, 02:39 PM

Check if there is any leakage in tank,if you found any leakage weld it.

seapuppy · 07-21-2011, 05:51 PM

Johnmartin...check your pm.....

can't weld a fuel tank

SP

deanries · 06-04-2012, 02:50 AM

9ball-

I have had this problem since I bought my boat "new" in 1992. Seems like the way the fuel tank is made having the vent and fill hoses so close together creates the problem. I know that filling the tank slow has been my life to keep from gas all over the back of the boat. Having the fuel hose high and filling flow on the bottom of the fill hose has had some success. Biggest reason it comes out the fill line is the vent has fuel in it leaving no vent to the tank. Must be backsplash in the tank. Not a lot you can do unless you want to change the tank, not an easy job by no means. Just wait until the ethanol has ruined your tank before you take on that task. Hope you are getting her fueled without too much mess and the price of gas.

Dean (deanries) "Go Big or Go Home"

pascavone · 06-04-2012, 03:18 AM

my 2800scr dose the same thing, but you expect it to act like your car... and your car only holds 20 gallons.

plus, the new cira 1990 EPA gas pump nossles have fume suction recover system, like a vaccum while your pumpin, so it alone is putting your tank under negitive pressure.

add to the fact that your fill line is 4 to 6 feet long along with your vent.

try to hold the nossle out of the boat a bit more, and remember the fuel in dropping into the tank, not forced like a pump, why because the pump had a pressure limit switch to avoid spillage... why every pump says do not top off tank....

9Ball · 06-04-2012, 01:42 PM

I had the same boat last year and the same problem, never could figure it out, but when I trailer it to the gas station, I always tried to make sure the bow was downhill of the stern, there was only one gas station in town that the pumps were on a little incline so I would always pull into the pumps going downhill....seem to help a little or maybe that fuel pump had lower pressure. I also found that the Fuel fill hose was about 6" too long and had which caused the hose to have a slight "U" shape, (Kinda like a trap under the sink).

Check out the Picture, This is the boat I have now (94-2000SC) when I first got it (what a mess

Click image for larger version

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Todd

rens914 · 06-04-2012, 09:38 PM

Quote:

Originally Posted by johnmartin348

Check if there is any leakage in tank,if you found any leakage weld it.

That's a quick fix and it probably won't leak anymore after that

seapuppy · 06-04-2012, 11:06 PM

part of the problem with refueling a boat and the fill port is in the stern ..tank amidships...the fuel line can't be routed well enough or short enough to prevent blow back....plus part of the problem is that the tank fill entrance is in the stern of the tank where the air will collect fwd..compress and force the gas back up and into the filler and out onto you....the only thing you can do is lower the bow....or have someone stand on the bow to get the bubble towards the back of the tank....

I have the same problem with my 340...it's a bear to fill up the tank....I've seen it shoot gas 3 ft into the air...

SP