XB-21 Fuel Tank Calibration

[Alli-drenaline Rush]

An interesting tidbit for those guys running 21s with the old style tanks (in boats produced up until late 2012 / early 2013)......... I managed to run out of gas on the lake during the last fishing trip (fish weren't biting, and I thought I had more fuel in the tank than I did when I felt the need for a few 91+mph passes).......

Somewhere between 13 and 18 gal the tank cross-sectional area gets noticeably smaller.... Makes sense that the upper part of the tank would fit over the built-in setback in the boat, but if you think that 4" of fuel level at the bottom of the tank is the same as 4" of fuel at the top of the tank, think again.... It's prolly half......

 

[GotMyAlly]

4" of fuel is about all I ever put in mine anyway........LOL.

 

[catfish123]

Probably.............you are trying to get it to run like your XB2003 did..........LMAO..........won't happen.

 

[GotMyAlly]

I dunno....best my 03 ever ran was 96 and change. My 21 has seen 98 and change. So technically my 21 is faster, with only 25HP more. But it sure gets better gas mileage! If i fill the tank up, I can fish 4 or 5 times before I have to revisit the gas station. The trolling motor gets REALLY good gas mileage. Even at the rally this year, I filled up on the first day and didn't top off again until the 4th day. Seriously, if you've never ran one of the Opti motors, you just can't comprehend the gas savings. I burn more in my truck going back and forth to the lake. My average fishing trip last summer burned about 7 gallons in the boat, and even less when I was night fishing.

 

[catfish123]

How many mpg are you getting? I know Matt and I both got around 5.5 mpg with the 225X's.

 

[GotMyAlly]

It's been a while since I checked it, but best as I recall i've seen around 7 mpg. But that obviously wasn't running balls to the wall, either.

 

[2003225X]

I'd be more concerned with running a motor like that "dry." Or is that not an issue?

 

[ssv1761982]

I'd be more concerned with running a motor like that "dry." Or is that not an issue?

Good question. The oil is pumped directly to the bearings so that should not be an issue. The injectors just flow straight gas, no oil.

At idle I think my Opti used .3 gals per hour and I think the 225x shows 1.3 gal per hour. Something crazy like that.

 

[2003225X]

Good question. The oil is pumped directly to the bearings so that should not be an issue. The injectors just flow straight gas, no oil.

At idle I think my Opti used .3 gals per hour and I think the 225x shows 1.3 gal per hour. Something crazy like that.

Not with a 280. They are premixed.

 

[ssv1761982]

Oops, I forgot Richard didn't run an Opti like everybody else with a bigger boat. GotMyAlly and your dad changed direction on the gas mileage so I got distracted.

 

[Alli-drenaline Rush]

4" of fuel is about all I ever put in mine anyway........LOL.

I've been wondering how you got that fat-azz 3L to put up big numbers lol

 

[Alli-drenaline Rush]

Oops, I forgot Richard didn't run an Opti like everybody else with a bigger boat. GotMyAlly and your dad changed direction on the gas mileage so I got distracted.

I've been thinking that XB2002 with a 200XS ROS would be a cool rig.....

 

[ssv1761982]

I've been thinking that XB2002 with a 200XS ROS would be a cool rig.....

True but I am content with what I have for a change. Runs good, fishes good, does everything I want or need. It is easy on gas too.

Actually it is a weird feeling not 'wanting'. :gone fishing

 

[xb03fs]

I want a 400 lb 7200 rpm limited 2.75 liter 250 hp opti with a sporty and a warranty

 

[GotMyAlly]

I've been wondering how you got that fat-azz 3L to put up big numbers lol

LOL, at the rally I had about 3/4 tank the day I ran 98.

In my experience, fuel doesn't make much difference in top end numbers. It's so far back, I don't think the effect is that great. Seems to have more of an impact on holeshot and acceleration.

I rarely fill mine all the way up just for fishing trips though. Fishing once a weekend or sometimes every other weekend, it might take 6 wks to burn through all that gas. I don't like letting this ethanol crap we have get that stale in my tank.

Now when I find non-ethanol and have the opportunity, I'll fill it to the top, even if I think it'll be in there for a couple months. I think even 2 month old non-ethanol gas is better than straight from the pump ethanol crap.

 

[Alli-drenaline Rush]

LOL, at the rally I had about 3/4 tank the day I ran 98.

Puttin' up good numbers there!!

 

[Alli-drenaline Rush]

Something weird is going on...... when I look at my profile pic on the PC it is right side up. when I look at it on an iPhone or iPad, it is upside down?????

Update: fixed it. iPad pic was upside down originally. Rotated on the iPhone, then uploaded to Photobucket, as opposed to trying to rotate in the PictureIT! software...... weird....

 

[GotMyAlly]

You could use RA's method. Run it dry, mark it with a Sharpie at 5 gallon increments as you fill it back up....

 

[Alli-drenaline Rush]

You could use RA's method. Run it dry, mark it with a Sharpie at 5 gallon increments as you fill it back up....

That's exactly what I did....... :cool

 

[GotMyAlly]

How much did it hold? The advertised 36 gallons or did it stop a couple short?