DF90a Throttle issue

[Mbusuttil]

hi all

I have a very strange problem and thought of posting it here for help.

I have a DF90a bough back in 2012 and last week i started having throttle control issues whereby after starting the engine and trying to add a little bit of throttle the engine just revs up to 2000 rpm and pulling back the throttle goes back to idle.

There is no possibility to control the boat at that rpm.

I removed the cable and tested it by hand manually and same result. I tried adjusting also the airflow via that small screw at the top but no results.

Any ideas?

Thanks in advanced
Mark