fuel delivery problem

[grizzlybars]

i have a 1965 model, 90hp johnson-mod#v4ml-11c. ser#j2547231. i have been fighting a fuel delivery problem with no luck. motor starts great, idles and runs to about half throttle with no problems. when throttle is advanced to above half engine begins starving for fuel. engine hunts up and down until throttle is brought back to about half. i have replace the following parts trying to resolve this-spark plugs, points and condenser, new plastic fuel tanks, new fuel delivery hose and fittings, replaced primer bulb again, checked belt timing, fuel bowl screen, fuel pump diaghram, all fuel hoses on engine, water pump impeller. 2 things also happened over the 4th weekend, as it ran out of fuel on 1 tank power picked up to normal as it leaned out. adjusted float settings thinking it was getting too much fuel, no good. also when someone is manually squeezing the primer bulb problem goes away while it is being pumped, adjusted floats again but no good, finally did a compression check on engine and got an even 65 lbs on all cylinders, is this low enough to not pump enough fuel at higher delivery needs? not sure how reliable my compression gauge is because engine just runs too good at idle and lower throttle to suspect that, also when bulb is maually pumped engine runs up in power and rpm normally. this is drivin me nuts, any help will be greatly appreciated! thanks.