Saddle tanks question

Yes, for some reason your one tank is not flowing, or you only filled one tank. They once siphoned, and will on older boats, between each other. Though they have anti siphon valves now and you must fill both tanks at the same level. They in theory should pull reasonably close in volume as the lines are identical in length. Though if a valve is stiff they will not. This is not the rear switching valve at all. BCB

No you just did what many are doing, and in years past they would have siphoned on the way to the lake, or even fishing. Unless you jumped right in and went running around. Then they would have experienced the same results you did. Here is a link to the fuel tank descriptions, though newer boats will not siphon between them as of the present year. BCB Teamhttp://basscatowners.yuku.com/topic/2145

They will only siphon if you have fuel in them, if the pick ups can catch air in the sloshing, then they will loose prime and not siphon. Otherwise they should siphon. See how it works from here, we think you may have been low. Any air in the line from slosh and it will not catch up.