Assuming your motors are Yamahas, the piece of the flush connection that attaches to the cowl goes nowhere. It is a dead end. In theory you could extend the hose portion to a fitting somewhere to make access easier. The fitting should be OFF when not used. There are garden hose adapters like shown but different gender that will do. You just need to select the ones that have the check valve that closes the flow when disconnected.. Note that these adapters can restrict the flow a bit as will a longer piece of hose that extends the flush hose. I would be careful about running the motor on the flush port only. ( Yes I know that Yamaha says not to do so but many folks do and in general, the motor won't overheat if just idled).