Does anyone know where the main tank fuel sender is? I have two round access covers in center but only the one towards the helm shows anything which is the fill line and the vent line. There are two rectangulart access panels to either side of center under seats. There is a small access cover on the starboard side which appears to have the sender but need to remove main panel to get to. I have one main and two auxillary tanks. Looking at only layout i could find the main tank is in center and two auxillaries to other side which would not make sense with the sender i can find. I saw another thread on here about a tank under rear seat. All i have there is the water tank.

The fuel sender should be an SAE standard 5 bolt pattern approximately 3 inches in diameter.

I've never opened mine, but isn't there a circular access cover between the two bolster seats under the carpet? Maybe that's it? I can check my manual tonight...

I just changed my 43 sending unit last nite it was under water tank under back seat next to fuel pickup lines

What kind of sending unit and where did you purchase it, I need to change mine on my 43.

the one i used was the old style with the arm and flote (I do not remember the name on the box) I have had two of the tube type go bad in other boats i got it at local marine supply store called marine sales in MI

I found it. There is a third large access cover under the back seat unfortunately directly under the support bar but you can get to the sender and the five screws. I am replacing with a Hardin Marine two wire fuel sender that i bought from CP Performance. The two emergency tanks are to either side of main tank which is what i thought originally. Someone had asked what size the main tank was on another thread i saw earlier. Mine is stamped with 144 gallons on the main and 25 gallons each on the emergency tanks.