Hello everyone and thanks in advance for any info you may be able to share with me. I just bought this 1990 sundancer( first boat ever) I had it out today and seem to be experiencing issues with the Jabsco head. It will not pump out waste...no paper or solid has been put in it, nor will it pull in water . The other issue was that at the pump out station it would not pump out. I made sure hose was tightly against the waste pump out opening , tried priming the pump hose with lake water but nothing helped. I also tried pouring water into pump out hole but after maybe a quart it acted like it was full but nothing would pump out of tank. Could I be looking at a clog? Also is there a seacock I am not finding for the head operation? Thanks in advance!