Yamaha 01 250 OX66 running rough. Trying to figure it out.

[Cslider]

My 2001 Yamaha OX66 250hp was running real rough when idling. Would turn off too. I checked compression and I am at 115 on all 6 cylinders. I changed the VST filter, had the fuel injectors cleaned as well by injector-man. New primer bulb and rancor filter. Also 3 new fuel pumps. As well as the filter replaced in the motor. What else could be still causing it to run rough? Please help me out on what I may have missed

 

[99yam40]

spark plugs maybe

 

[Cslider]

I did change and put new spark plugs too. gapped correctly as well.

 

[flyingscott]

What about the oxygen sensors?

 

[Cslider]

I did clean the O2 Sensor and the barbell. Had some carbon build up on it. Still ran rough so I changed the 02 Sensor to another one I had. Still same thing. Was raining all day today so wasn’t able to work on it more. But going to check all the coils and spark tomorrow hopefully.

 

[flyingscott]

Gonna need to scan it. Who cleaned your injectors? Was there a flow and pattern test done to them?

 

[crazy charlie]

Ignition wires?? Run it in the dark and look for arcing or just change out the wires.Charlie

 

[Cslider]

Gonna need to scan it. Who cleaned your injectors? Was there a flow and pattern test done to them?

Yes. I had them done professionally and got the flow chart back. All even now and cleaned with new filters

 

[Cslider]

Ignition wires?? Run it in the dark and look for arcing or just change out the wires.Charlie

Going to try that. Sounds like a good idea.

 

[Cslider]

Bad stator. Replaced and running great again.