88 Wellcraft 170 Classic, 3.0, Alpha One. Bought boat late last season, boat ran good but decided to do total tune up before this season. Plugs (mr43t AC Delco), cap, wires, rotor, condenser, fuel filter (all Sierra parts). point set at 30 degrees dwell, Timing at 8 degrees before TDC, idle mix set by manual, idle speed 650 in gear. First trip out this season, boat started great, idled out waiting for friend to park truck and trailer, put it in forward and it died. Wouldn't restart. fiddle wit a few things and it started back up and was flawless the rest of the weekend. FF about a month. On vacation for a week, began having intermittent VERY rough idle, enough so, no sense even trying to put in gear. It had rained a ton, boat was in covered slip but rain was sideways so I though maybe water pushed its way up the vent. Added some Heet treatment, problem cleared and we were on our way. Next day, same issues, same fix, same result, Yes, rained that much again. Next day, started great, idled through no wake, took off, then again, same issue but could never restart. After many hours troubleshooting, I'm fairly certain the issue is in the ignition system. Running on muffs in the driveway, problem is still intermittent. put all old tune up parts back on, (yes, I saved them) no change. Comes and goes. only issue I have found at all, + coil voltage is at battery volts when running, should be lower due to resistance wire. oh, also i have installed new coil with no change. Tried disconnecting tach from system, no change. ANY ideas would be greatly appreciated!!! I'm at a loss as to what to try next.
