DF40 Rough Idle and dies above 2000 RPM.

[billyocean1642]

i have a 40 hp 4 stroke on the back of a 17 southern skimmer. bought it used. first time out ran fine all day headed back to ramp at wot and motor cut out and shut off. restarted engine and ran ok up to 2000 rpms. after that shuts off. I replaced all fuel lines and fuel bulb and same issue. also replaced fuel water seperator as well. any ideas as to what could be going on. i am mechanically inclined so if i can figure it out i can fix it.

Also, need to add that when it shuts off check engine light comes on. I am thinking it could be high pressure pump or injectors could be clogged. Compression and leakdown test is good. I am in the process of changing the impeller as it has a very weak water flow and someone said it could be a temp alarm knocking into fail safe mode. Any ideas are appreciated.

[artdf175]

When the alarm sounds are you getting a series of beeps?
Should be able to count beeps Pause and 2nd set
The safe mode usually has a 3000 rpm top limit
Impeller- if you don't have the history of maintenance then very good idea to replace the impeller - the full kit
It sounds more like starving for fuel
When this happens did you notice status of the fuel bulb?
It's also been known and easy to forget to open the fuel tank air vent
You didn't mention the inline fuel filter under the cowling pre low pressure fuel pump, look for debris-Which brings up did you test the LP pump?
Inside the housing for the high pressure pump there is another filter that has created running problems
One last thing I also mention is getting a copy of the full service manual
Art