1975 70hp johnson. starts good, idles good, runs at trolling speed, dies when throttled further every time. checked compression (130psi all 3)changed fuel/oil with new, changed spark plugs, changed fuel lines from pump to carbs and tank to motor c/w primer bulb, checked fuel pump diaphram and filter all good. checked fuel tank lines inside and screen. carbs are absolutely mint shape. cleaned/checked flywheel/magneto contacts. did the spark plug wire pull test and all cylinders fire properly. motor revs up fine with hand pulling carb linkage out of gear but dies when in gear. i was told that main jets are plugged and to pull carbs apart and try cleaning them. motor was always fogged in the fall when parked.<br />does this sound reasonable, or is it an ignition/powerpack thing? also how hard is the primer bulb supposed to get when you squeeze it? i have two different fuel lines and both stream fuel out when you pump and push the ball out of the way, but one seems to get real hard and the other is softer. ps the motor doesn't run any better if you pump the bulb anyways.<br />appreciate an expert opinion!! thanks