Fuel Tank for 20hp?

I have a Johnson 20hp 2 stroke on my 1655 Lowe.
All I have right now is the 3g tank from my old 9.9.

How much fuel will a 20 burn in a normal day of fishing?

Your 3 gallon tank is cutting it to close. I normally use 3 gallons per trip but sometimes up to 5 gallons. I am running a 25hp Evinrude.
It all depends on the body water size that your fishing if you will need a bigger tank. Either upgrade to a 6 gallon tank or take a 2 gallon reserve can with you.

Agree time to move up to 6 gal tank. Better safe then sorry.

You will get about 6 to 7 mpg with a properly tuned 20 hp.

So you guys think 6g is enough for a hard day?

I was thinking about a 12g.

I'm thinking the same thing :LOL2: I just put a 20 HP on my boat this year and wow, it's a hog compared to my 8.

I run 24 mile round trips often over the summer with my 14' jon with a rough tuned 20 horse johnson and go through about 5 gallons to do it. Loaded with beer and camp equipment and the wife the same trip takes about 7 gallons. It just depends on what you call a hard day I guess. A six gallon can under normal conditions works for me, I stack on another 6 gallons if its gonna be a long weekend of camping and fishing.

I have a 25 hp motor and have a 12 gal tank under a small deck up front.

Pruitt1222 said:

A six gallon can under normal conditions works for me, I stack on another 6 gallons if its gonna be a long weekend of camping and fishing.

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A six with my three for reserve would probably work for everything I will do.
Still I may get a bigger tank just so I won't have to worry about fuel.
Plus if I want to make a long run I'll just fill it all the way up instead of hauling cans.

This is general rule of thumb.

0.1 gallon/hr per 1 hp at (WOT) wide open throttle

2 gallon/hr per 20hp at (WOT) wide open throttle

You will find the that you will get better gas consumption and mpg efficiency if you run you motor approximately 3/4 throttle.

Now with the above statement being said, older motors tend to be a little more gas thirsty than the newer fuel injected motors.

Get to know your motor and boat regarding fuel consumption. If you are embarking upon a distant trip, then bring an extra supply of fuel and oil.

Found this link regarding hp, rpm and fuel consumption....very interesting and informative.

https://www.marineenginedigest.com/specialreports/fuelflowchart.htm


Hope this helps. Get a 6 gallon tank and bring your 3 gallon as a back up. If you use up the 6 gallon tank then time to head back to the dock with the 3 gallon back.... :LOL2:

cajuncook1 said:

If you use up the 6 gallon tank then time to head back to the dock with the 3 gallon back.... :LOL2:

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This is exactly what I don't want to happen.
Interrupting/cutting short a fishing trip cause I wasn't prepared.

Maybe it's the Boyscout in me.

I am kind of underpowered with this boat. May be running near full throttle quite a bit.