Have a strange issue where the rear two tanks are somehow draining into the main center tank. After the side tanks get empty its causing the starboard motor to shut off and its a biatch to get it restrarted. any suggestions as to what would be causing this?
I can fill all three tanks and it will cause fuel to overflow out of the center tank after running for just a short time. It seems to draw outta of the outside tanks and return to the center tank.
Boat is a 1998 38' Scarab with twin 502 efi Mags.

I got the same issue with mine. I fill all three tanks but turn off the side tanks. After the center tank get near empty then I shut off the center and open the side tanks. In a way I use my side tanks like reserves. I learned this after running out of gas twice. Good luck!

I guess check your cross over valves and make sure they are in the correct possition...might want to also check for water in the tanks...that can cause some wierd crap to happen.

we have checked the valves in the engine compartment and they appear to be working ok. Somehow it is siphoning out of the small tanks into the big tank.

i think the fuel manifold was designed to run with only one valve open or drawing from one tank at a time. Are you running with more then one valve open at a time?

Yes we run with all of them open. It was fine all last year. This year it appears to be getting worse.

If it helps the boat matches yours almost 100% same paint scheme lol.