DF 350 wont go above 3500rpm

[Plumber1969]

We have cleaned the vst, filters have been changed, cylinders all compression tested fine, plugs good. The boat idles fine, but will not go above 3500 rpm. We had a new powerhead installed under warranty 1.5 years ago and then we have had the newer lower unit installed but we are stumped on this. Any thoughts?

[Moonlighter]

The best way to diagnose this will be to connect it up to the SDS and see what is showing and do some testing.

Otherwise it can be shooting in the dark.

anyway…. Have seen several similar posts on other forums where fuel lines from tank to bulb had broken down internally causing fuel restrictions, became obvious when the lines were taken off fittings and looked inside the area where they connected. Sk worth a look at that.

How do you know that the spark plugs are good? Under load a bad plug/lead can break down but be Ok at idle.

[Solarman]

Any chance this is related to the neutral safety switch on the motor?
The 3500 rpm limit usually indicates this?

Good luck.