87 200 HP Evinrude Intermittent Ignition

[bigboat606]

My 1987 200 HP Evinrude has began to run rough intermittently. The engine sounds like several cylinders are ?missing? or dropping-out for a few seconds (maybe 2-5 seconds?) and then picking back up again with this cycle repeating during the ?problem time?. This problem is very distinct and comes and goes. The engine can run for long periods, maybe 30 minutes, without problem. Then the problem can appear without warning and last the rest of the trip ? maybe 45 minutes so far. This problem appeared suddenly two trips ago and repeated again this last trip. This ignition ?miss? happens at all speeds from idle to cruising. It happens at all engine temperatures - at cold start-up and after cruising for a time. This is truly an intermittent problem and I can?t get this problem to occur on the trailer where I can perform diagnostics. Anyone have suggestions that may help me trouble-shoot this one? Thanks in advance.

 

[jonesg]

Re: 87 200 HP Evinrude Intermittent Ignition

On the trailer, try engaging fwd gear and spin it up slightly a few times.
If its the shift assist switch you'll encounter the problem.

Or disconnect the switch next time out, see what it does.

Could also be dropping into SLOW mode, when it acts up disconnect the port sensor.
Got a factory manual?
www.outboardbooks.com