Re: 1985 90hp inline 6 murcury "tower of power" help!
A couple of ways you can tell if you're getting water circulation when running a motor on the flusher, in the absence of a telltale:
1) Feel the exhaust manifold cover, it should be Stone Cold. If it's too hot to touch, you're not getting water thru the block. Exhaust beats directly on the baffle beneath the cover, and the Whole Mess gets hot real fast when there's no water. So you'll know right away.
2) Water exits the block and goes down the middle (exhaust tower, aka 'center section', aka 'mid'), and right out the center of the prop. If the water running out the prop is noticeably warmer than the water supply going into the motor, you've got water circulation thru the block.
Needless to say, it's best to have that telltale working, cause it's a lot easier to see that underway than to have a helper back there taking the motor's temperature all the time!
I'd try what the O.P. said, the plastic piece at the end, or the hose itself, may be plugged with debris. A puff of compressed air up the telltale is usually all it takes to clear things up.
HTH...........ed
