Gas tank reserve capacity...

[cdc2010]

I'm assuming gas tanks have to do with the boat and not the motor, but in my z21 with two 26 (?) gallon tanks, I ran out of gas in one of my tanks the other day. (I had the gauge reading tank 1 showing 1/4 tank, but the mechanical knob had me unknowingly using gas from tank 2.)

Anyway, I put 5 gallons in the bone dry tank 1, get to the lake and the needle is way down at or below the E. Like I had never put gas in it. I thought maybe I needed to right around so the sensor would pick up the new fuel, but it never did. On the way home, I stopped and put 10 more gallons in and it brought it up to about 1/2 tank.

So my question is: do these tanks have a rather larger "reserve" amount of fuel (like 5 ish gallons) that is in there when the needle is on E? Seems so, but I've never let it get to close to E without refueling before.

[06 SB]

These are not ATV gas tanks. There is no reserve in these tanks. If anything they actually seem like there is less capacity than listed.

[calfish1]

there is no reserve in these tank. it depends on who and how they installed the sender height. best way to judge is use your 'gallons used' on your smart craft gauge. its close but still dont let it get that low

[mikesxpress]

No "one size fits all" on these tanks. The two tanks on my Z21 Intracoastal can go down to empty with no needle bounce and still have 4-6 gallons left.

[cdc2010]

No "one size fits all" on these tanks. The two tanks on my Z21 Intracoastal can go down to empty with no needle bounce and still have 4-6 gallons left.

Thanks. This sounds like what I'm experiencing.

I may experiment by letting my second tank run all the way down to E on the gauge and then literally to empty, and see how many gallons I have to put in for the needle to begin to move.

[dean c]

I’d recommend a merc monitor. Zero it out at each fill up. Mine is accurate to the gallon for fuel burn.

[wmitch2]

I wouldn't run a gas tank all the way to Empty. If there's any debris in the bottom of the tank you'll suck it up into the fuel line and filter. Not a good Idea !! I have a Merc Monitor that shows Fuel Used. I check it before I leave home and always add 10% more to what it shows. I never run my tank lower that 1/4 for MANY reasons.

[bill.s]

Pick up tube is generally above the bottom of the tank in order to not pick up debris/sludge from bottom of the tank. The screened end of the pickup tube usually is high enough to leave about 10% of the fuel in the tank.

[howieranger]

The gas tanks do not have a" fuel reserve" they have "useable fuel". The fuel pickups do not go to the bottom of the tanks and there is not a depression in the bottom of the tanks so the pickups cannot pickup all the fuel and debris off the bottom of the tank. The usable fuel tends to vary a bit from boat to boat depending on the depth of of the pickup and variations in the tanks themselves and what angles the tanks are at different speeds and sitting on the trailer. Boy do Miss having two tanks.