Fuel gauge accuracy/adjustment?

[thunder550]

How accurate is the fuel gauge on the Cobalts? According to the manual I have a 78 gallon tank. I filled it completely full for our Havasu trip (it was showing below 1/4 and I could only get about 45 gallons in it). Might have maybe put 12 hours on it over the past 4 days and it's showing almost dead empty. I can't fathom how we could have burned more than 40-45 gallons tops, but if the gauge is accurate we went through almost double that. Any ideas on gauge accuracy? Is there any adjustment to them? Do they wear out and go out of calibration over time?

[Bfun220]

My fuel gauge seems to be accurate. Not sure about calibration ? Never heard of someone calibrating it but maybe someone with more experience will chime in.

[Big Block Power]

My 2004 200 was not accurate either. On empty I still had 1/2 left. I never looked but I believe it's still just a float on a metal rod. You can bend the rod or the resistor part of the sender could be bad. Just fill it up when you get home and see how much she takes. One of my boats had a cork float and it got gas soaked and was heavy I just changed that one to a plastic float. The sender should be easy to get too. The access hole it's just in frt of the engine normally.

[thunder550]

My 2004 200 was not accurate either. On empty I still had 1/2 left. I never looked but I believe it's still just a float on a metal rod. You can bend the rod or the resistor part of the sender could be bad. Just fill it up when you get home and see how much she takes. One of my boats had a cork float and it got gas soaked and was heavy I just changed that one to a plastic float. The sender should be easy to get too. The access hole it's just in frt of the engine normally.

So your boat was a cork soaker?

I'll have to pull the sender out of the tank when I get home and see how deep the fuel level is. Old school, time to dip the tank!

[Big Block Power]

My 2004 200 was not accurate either. On empty I still had 1/2 left. I never looked but I believe it's still just a float on a metal rod. You can bend the rod or the resistor part of the sender could be bad. Just fill it up when you get home and see how much she takes. One of my boats had a cork float and it got gas soaked and was heavy I just changed that one to a plastic float. The sender should be easy to get too. The access hole it's just in frt of the engine normally.

So your boat was a cork soaker?

I'll have to pull the sender out of the tank when I get home and see how deep the fuel level is. Old school, time to dip the tank!

Just fill it up. We're going to burn it up in two weeks anyways

[Driller]

My gauge is pretty accurate. Do a mental calculation based on the gauge prior to filling and it is usually quite close.

Gauge measurement with the boat static in the water.

[jhnmdahl]

Mine is pretty accurate too. I’d pull out the foot assembly and take a look at it if you’re getting inaccurate readings.

[Big Block Power]

Mine always reads full At full throttle and empty at idle. Does that count as accurate?

[NautiGirl]

This one was the one thing we had the dealer replace at purchase this summer...went out for our sea trial and they guy said he stopped for gas on his way because when he checked the boat it was on E...gas spilled back out at him at the pump since he figured he was working with an empty tank...oops!

Sending unit replaced and the boat came with a full tank!

[AsLan7]

FWIW, our fuel sender's have always been fairly accurate. It is one of the tests we do on a just purchased boat. Never had any issues down to a quarter of a tank.

With that being said, I never trust the gauge and always keep the boat above a half tank after that initial test. You never want to be "that guy".
.

[cmattj]

Funny subject as we take for granted that car tech with low fuel warning should eventually be in a boat that cost 3 times the amount..
Geeze

But I've always distrusted my fuel gauge.. it is accurate once I slowly sneak up on running it down and topping it off.. deduct to capacity and gauge the real level..

After a few "Seinfeld " see how far you can take it on fumes....And with your "boat us" card On hand you'll know right?!!

[AsLan7]

After a few "Seinfeld " see how far you can take it on fumes....And with your "boat us" card On hand you'll know right?!!

Love that one, Matt!

[thunder550]

So after reacquainting myself with the 502 fuel consumption I think it's ok. Mine burns mid 30's per hour wide open and 11-15 cruising between 3000 and 3500. That lines up well with the 7-8 hours I think I put on the engine and tank size. I think I was confusing GPH with MPG.

I did pull the sender out of the tank today to check, ran it up and down manually and watched the gauge, everything jived. Also measured tank depth vs sender depth at empty and they are pretty close. My math was just wrong.

[AsLan7]

So after reacquainting myself with the 502 fuel consumption I think it's ok. Mine burns mid 30's per hour wide open and 11-15 cruising between 3000 and 3500. That lines up well with the 7-8 hours I think I put on the engine and tank size. I think I was confusing GPH with MPG.

I did pull the sender out of the tank today to check, ran it up and down manually and watched the gauge, everything jived. Also measured tank depth vs sender depth at empty and they are pretty close. My math was just wrong.

Nice job on that, T550! Doesn't get much more accurate than that test.

[thunder550]

Tank was dang near empty after our Havasu trip, verified when I pulled the sender last week. I put 34 gallons in it today, which should be around half tank (73 gallon capacity, and a couple gallons already in it). Tank registered 3/4 on the water. Good to know that 3/4 on the gauge is really about 1/2 by capacity.