2014 DF90A revving high after being under load

[galilee]

We've got a 5.5m aluminium boat with a 2014 DF90A which has done about 500 hours. AT the weekend we had to rescue a boat with engine trouble and tow back to harbour....smallish fibreglass boat with 3 guys on board. It put the engine under a bit of strain (ie high revs and not moving very fast for an hour or so)....now the engine is revving high in idle and so not smoothly engaging in gear.

I've got it booked in for a checkup but they can't get to it for a couple if weeks....I want to use it in the meantime, but is this wise?? Any tips or things I can check myself?

Thanks.

[Moonlighter]

Revving high in neutral or at idle throttle or erratic revving are often associated with IAC valve fail issues.

I would suggest not running it again until this is diagnosed and fixed, there have been a few cares where faulty IAC’s caused damage to the ecu.

[UrbanBatic]

You can find the manual here on manualslib.
AFAIK K9 and K14 should be very similar outboards.
Page 39 (0B-13) in the Service manual is about Idle speed and IAC in general.
Pages 192-193-194 (1G-9 and on) from the same manual are about IAC Valve Control Mode.
If you have any option of getting hands on SDS you can speed things up and look the things up yourself. Or at least measure the signal on cables to the IAC with a multimeter if there is any signal at all. (p. 193)
At this point, we have to say thanks to the user Murray for SM.