On my 215 there is a lever in the bilge to switch the pump between the raw water washdown and the baitwell. I'm not sure if the 170 is that way or not. But if I've switched it to the washdown and then try to use the baitwell, the pump will run but no water will come out. That is probably not your issue though since the baitwell pump works for you sometimes after going on plane awhile. I'll quiz the factory folks to see if they have any ideas.
