The Marelon bypass valves for my head
are completely locked up. I have no faith in them. I am changing over to bronze
ball valves. I don't think the price
difference is worth the hassle and the danger
of not having valves working when you need them to work
. Ask anyone at a boatyard who deals with these valves, it is very common occurrence for their handles to break off as a result of them seizing up.