Ideas to drain reserve tank

Direct line from pickup to primer bulb into tank on ground. Siphon effect
If there is an antisiphon valve on the tank, that won't work. The hose has to be lower than the bottom of the tank also and finally siphoning using the pickup will not get the gunk on the bottom since there is a space between the bottom of the pickup and the tank bottom. Honestly, I have never had much luck siphoning.
 
Adding a deck plate isn't a structural issue. But if you can get your hands in there well enough to cut it apart, then go that route. And then get the "swingarm" style sender. If you want to put the same kind back in, though, it seems like you're gonna need the deck plate for install anyways.

FYI... obviously avoid dropping cuttings into the tank - the pipe cutter will avoid that. BUT, you also have to avoid dropping the tube back into the tank as you cut it. So maybe use some good tape below your cut to hold onto the piece, just in case. Or... cut through ONLY about 3/4 of the way around and then maybe you can bend that part over... cut the next section 3/4... etc.
 
If a new style wema will fit in there without cutting the boat, , cut the old sender out.
That's what I would do, one day you may have to change the sender as it may become inoperative . It is stupid that you can'r remove the sender without cutting the boat.
 
So I was able to remove gas pope from a pick up tube. Had to cut it, luckily theres slack in the gas line. I put a 1/4 inch gas line down the pick up tube and attached that to a gas line with bulb and suctioned out what you see here. The third gallon I pulled out was nearly all gas with very little water at the bottom. My hand is all busted up working in that small space.62250.jpeg
 
Im going to run 1 motor on that tank and the other on the main tank. I'll pull the filter off to drain any residual water from the reserve tank.

Thanks for all your ideas many useful info and ideas. You people respond so fast it helps so much because online research take so long.
 
If a new style wema will fit in there without cutting the boat, , cut the old sender out.

I'd do this. There were a couple gallons in the bottom of my tank on a 228 that I needed to remove after the fuel pickup couldn't pickup anymore. Cut the sender, pull out all old fuel. Rinse the tank with some alcohol to remove varnish and you're off.