We have a 2003 Honda 200 4 stroke outboard motor with 650 hours on it that we use in salt water. We have had zero issues with it, but took it out for the first time since winter (sat ~3 months) and the check engine light is coming on and an alarm sounding when we idle after going over a certain rpm. It is an intermittent alarm (~1 sec on, 1 sec off). The motor does not shut off and there are no signs of issues other than the alarm/light. If we turn it off and back on, everything is fine.

We took it out a second time and determined the alarm sounds and check engine light comes on after going somewhere between 3000 and 4200 rpm. We rode at 3000 rpm for a couple minutes, then idled, and the alarm/light did not come on. After going again at 4200 rpm, the alarm did sound when idling. Does anyone have any idea what may be causing this? We have had this motor two years without problems and it doesn't seem to be in any kind of distress. The closest Honda tech is several hours away, so are hoping someone has had a similar experience or may be able to offer some guidance or suggestions.

Thanks!