High idle 1988 225 evinrude

My wiring diagram shows the yellow-orange wire that goes to the solenoid also going to the power pack. What purpose does it serve, and could it be causing my quick start to not disengage. I have looked at the troubleshooting guide, but cannot solve this problem. Could a bad key switch possibly be the culprit? I also have a slight back shush on one carb, possibly from a faulty reed block. Could this cause a fast idle? Idle timing backed all the way off and I still have 1400 rpm. new stator, timer base. Grounding temp sensor has no effect. Checked for air leakage with carb cleaner. took apart fuel pump looking for holes in diaphram. No luck. I believe power pack is good, and I think it drops out of fast idle when it warms up but idle stays real high. Did sink and link. Possibly a leak from worn out throttle body? HELP