I have SmartCraft with my 6.2's, like Dave M said ,it's pretty accurate telling fuel used. Once filling the tank to the rim [ 85 gal ] the SmartCraft continuosly monitors my gal/hr and fuel used. I don't rely on the mechanical gauge much [ have the Livorsi sending unit as a backup as do with the other mech gauges] as long as the SmartCraft works.The Livorsi sender still works, but occasionally need recalibration with the two pots on top of the sender head unit.

I've got a fuel guage problem as well. I have the capacitance style sending unit with the empty/full pot on the top that I got from CP awhile back. I've cal'd and cal'd, and still it's goofy. Was showing 1/2 tank this past weekend on the Mississippi at cruise, slowed down for a wake, showed empty, back on the throttle, back to half. Filled my 50 gal tank when the gauge showed half, took 45 gallons !! I'm not sure what to do anymore. I had purchased another one of these sending units from CP about a year ago, and it was an "auto cal" version. Looks the same as mine, except no pots. Put that in a diesel tank for our club snowmobile groomer. Havn't received a whole lot of feed back on that set-up. May be a better answer for my application. Not sure..........

I have my tank setup with a new float sender that shows i'm at empty with about 10-15 gals left. Just bend the float arm to show empty wherever you want it. Unless you are running flow senders I have found that to be the easiest setup for me to know exactly when i'm getting low woth some "reserve"

Maretron makes those type of fuel senders, NMEA2000.

MY 252 was one way and now my 342 is the other.

252-Fill it up, and run it for days until it moved off full, but when it was almost on E, it was really almost on E. fill up with take almost the full amont the tank held. I liked this as i know E was E, and based it on that.

342-- fill it up and can make it come off full after a day of running around... keep running it until almost E, and then you fill it up and it takes 65 gallons....... well somethings not right there... it hold like 145 gallons.... SO E is 1/2.. but you cant see anything below that cause I am not going to run around like that. want to make this boat like the other one...

Then bend the float arm up a little bit and go retest it. this is not rocket science, you have to fine tune and tweek to get the end result you are looking to achive.

This is my plan, I just have never seen one out. I know where to acess the tank, and sending unit, just have yet to tackel the job, and if someone had a pic it would be nice.

also dont want to bend it so much that it never goes to E.. that would be bad.

No it's not rocket science but it is a bit ore complicated then that. If you read my origional post you would have noticed that I was talking about how the location of the sender in the tank along with the angle of the boat at rest in the water drastically effects the accuracy of the fuel gauge. Bending the foaat arm will not help with this issue if your boat doesn't sit flat and the sender is mounted midway in the tank.

If the fuel pickup tube is in the rear of the tank then I would set it to measure acurate when boat is at rest. If the tube is more towards the center of the tank then set it to measure acurate on plane. You need to get it to a point you can understand either on plane or at rest, location of the pickup tube is going to give you a starting point to work with. Take for instance if it is in the rear, and you have a quarter tank of fuel, once you get up on plane and the fuel levels out across the bottom of the tank, you may uncover the pickup tube. You may as well be empty unless you are going to idle all the way back to the Marina. You need to know the location of the pickup and the sender unit if they are not incorporateted together to get started.

I know my sending unit is at the front of my tank. but after that I dont know where the pick up is.