How do you adjust valves in 5.7 liter boat engine when factory setting ie zero lash plus one turn leaves valves open or too tight?
The way you explain it it sounds like your engine has hydrolic
lifters. With these I have always tightened the rockers until the
pushrod gets hard to spin and wont move up or down and then ONE
HALF TURN not a full turn. The valves might open but within a
minute or so should close. This is cause by the lifter bleeding off
leftover oil in it. Hope this helps.