Small Fuel Tank -Fuel Gauge Problem ?

[JROMY]

I have a 2000 Checkmate 259 Convincer that has appeared to have only a 35-40 gallon fuel tank. Every time the gauge read empty, I would put another 35-40 gallons in the boat. Then in my infinite wisdom I got to thinking that this was probably a bit strange to have a boat with an extra small gas tank and I contacted Checkmate. They assured me that all these boats were built with approximately 75 gallon tanks. So...how do I fix the gauge so it reads correctly and/or how do these work exactly? The gauge is a Gaffrig. Thanks.

[mcollinstn]

Buy a new sending unit. Read the instructions fully. The length of the float arm and the depth of the float arm pivot matter. It also matters how far forward or rearward the sender is located, but you don't have much control over that other than by "aiming" the float arm forward or rearward from the sender hole.

I have probably had to " tweak" the sending unit on every boat I've owned except for two that I own now (a Sea Ray cruiser and a Formula).

One boat showed 1/4 tank when dry and all of the others showed empty with plenty of fuel remaining.

Adjusting and rigging a new sending unit is not difficult, you just need to follow the instructions to the letter.

Luck.

[JROMY]

Thanks. I'll give it a shot.