Volvo 4.3 runs rough under power

[mjp62]

My 2005 Four Winns Volvo Penta 4.3 engine runs rough, and back fires when I Throttle up . It idles great. I changed the gas separator And cleaned the screen at the carb .
the temp is 165 and, I have great oil pressure. It was running fine at 25mph . when this started yesterday. I can't figure out what to check next.
Any help would be appreciated .

 

[Ciera2450]

Re: Volvo 4.3 runs rough under power

If you have ruled out fuel issues, I would move on to ignition issues.
You may have better luck in the volvo section of the forum.

 

[bassmantweed]

Re: Volvo 4.3 runs rough under power

Simple as it sounds check your spark plug wires and make sure they are firmly connected........ this lesson just cost me $105 at the dealer. I had knocked one of mine off and did not know it.