This is weird. The tanks have been plumbed the same way since I originally put the boat together. Two of your standard 10 gallon 8" aluminum gunnel tanks. Draw from the top so standpipes in both. -8 AN to a T, then -8 AN to a filter, -8 AN in and out of the pump and so on. I just put on some new carbs and a bigger (more pressure and volume) mechanical fuel pump. Finished up plumbing all the new pieces/parts and went to turn it over. Found I wasn't pumping fuel. Chased it all the back to the T. If I connect one line/tank at a time, she'll pump (either line/tank). As soon as I introduce the T and second line, it stops and I got dick. Both tanks are half full (verified).
I'm going to put a manual tank selector on it and I know it'll fix it. The puzzling part is why did this just now start happening? Granted I've never let my boat sit this long without starting it, and I know all the fuel in the lines and filter had evaporated and it probably lost it's prime, but I'm still puzzled.
The new fuel pump is a mechanical and so was the one it replaced. I've been doing my testing (chasing down the lines etc.) with an old Holley red I use for doing oil changes. The Holley is positioned as low as I can get it since I know they don't like to pull up hill and like I said, it'll pull from either tank while sitting in the same position. It definitely seems to be an issue with the T and way I've got it plumbed. I just don't get why.
Anybody recommend a good manual fuel selector/valve?
Last edited by Squirtcha?; 04-06-2014 at 11:47 AM.
Sounds like you're testing the tanks with an electric pump in place of the tee, one tank at a time. Did you try hooking the electric pump directly to the tee as well, or up where the mechanical is using the same line that feeds the mechanical.
It could be the line from the Tee to the mechanical pump has an air leak. It will never pump if the line from the tee to the mechanical leaks.
Sounds like your sucking air at the T. I run -10 from tanks to tank switch valve then thru filter to pump,-12 from pump to reg. -8 out of reg to carbs.
are your lines from your tanks exactly the same length to the T?
Yep. Just found it. The line from the T to the filter was sucking air. It looked fine but she's leaking like a seive. Pressurized it with air and there must be a 3-4 inch split where it had a bend in it.
I figured I'd just hookup one tank an get her started until I could get the selector valve. When I still wasn't getting any fuel, stumbled across it. The line looked fine visually. Downside to braided line I guess.
Yep, lines are the same length.
Nice work guys and thanks for the input.
Last edited by Squirtcha?; 04-06-2014 at 01:52 PM.