Gas tank size

ElkHunter2015!

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Dec 1, 2015
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Anyone know the gas tank size on a 1991 Javelin 409? I want to winterize it. It has some gas in it, but I do not know how much (the gauge is broke). I'd like to fill it up and add some stabilizer, but do not know how much to add.
Thanks.
 

Chris1956

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Gee, we can guess. How long is the boat, and how much and what kind of motor? Any idea if you have 1/4 tank, 1/2 tank or some other fraction of a tank of gas?
 

jbcurt00

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How long have you had it?

How do you determine how much gas to put in when you fill up before you use it?

If its got a below deck tank, is there an access port to reach the fuel sending unit? You might get lucky and be able to see the tank label, which should have the capacity on it.

Its a 20ft bass boat rated for up to a 200hp OB, I dont think its going to have a small tank.....

A guage reading of any fractional amount of a tankful isnt going to tell you how much gas is actually in the tank. Unless you know capacity, and even then the guage wont be 100% accurate anyway.
 

Silvertip

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Fill it up and put an amount of stabilizer in it equal to or slightly more than needed for the amount of fuel you added. You can't really use too much of the stuff (especially if you use Sea Foam). And just so you know, the gauge may not be "broken" but very likely just a wire popped off or the connection on the sender in the tank is bad.
 

Scott Danforth

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welcome aboard

a quick google search shows a 50 gallon tank for a javelin 409T, however there are 4 models of 409. is this a new to you boat?
 

jrttoday

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when in doubt, pump it all out. Then fill it back up paying close attention to the gas pump :lol:
 

JASinIL2006

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You can always overestimate the amount of fuel and then put in enough stabilizer for that. I think you'd have to add an awful lot of stabilizer before you overdosed your gas....
 

ElkHunter2015!

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Thanks to everyone who responded. It is 1991 model that just says 409. I have had it since the spring, but have not used it much. I generally put in gas in batches of 6 gal. I had the oil mix unit disconnected so I need to mix oil with the gas.
Looks like I need to improvise a dip stick to get a relative amount and then fill it up and add accordingly.
 

Watermann

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You can always repair the broken fuel gauge problem, it's usually the sending unit that goes bad but sometimes the gauge. There's a bunch of guys here that love to remote trouble shoot stuff like that.
 

Bonus Check

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Apr 19, 2015
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This is probably a good time to pump the tank down to zero saving the mixed fuel you pumped out. Then you can either store the fuel pumped out over the winter and leave your tank empty for the winter. (my tank is empty for the winter). Come spring time you can put the saved measured mixed fuel back in the tank and then top of 6 gals at a time of fuel and oil mix to determine how much fuel your tank holds. That way you have the freshest fuel for the new year.

Or

Skip the saving the pumped out mixed fuel and go ahead and pretend its spring and fill the tank back up.

Either way, you can get an accurate determination of the tank size and amount needed to top off.
 

smokeonthewater

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If you're up for one more run this year, pick up a 6 gallon portable tank... Fill it.... Head to the lake and run till the main tank is empty.... Run back on the 6 gallon tank... In the spring fix the gauge and fill the main tank and presto you will know level and capacity.
 
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