I’m have surging issues with 2006 BF225 (about 350 original hours), where I had to prime the fuel bulb and it would worked for a little bit (30-40 minutes). I took in to the shop. They found and replaced a cracked fuel line and fouled plugs with black soot around the idle exhaust ports. VST cleaned, HP and low pressure fuel filters replaced. Racor fuel filter replaced. O2 sensor about 1 year old and the thermostats are about 1 year old as well.
I ran it for 7 hours straight no issues. Then the surging came back. It runs at 4200-5000 rpms and then all of sudden it surges until it dies or I bring to idle. The first time I thought maybe it was water in the fuel so I drained the racor water filter but gas looked great and I primed the bulb - ran fine for 30 minutes. It happened several other times where I just stopped and shut it off and restarted. Ran fine after restart but 30-40 minutes later it would surge again. This surge is like it is starved for fuel and it is a major drop in rpm – going from 4400-5000 to 1500 rpm or it dies. It later ran fine back to the harbor which was a 2 hour run. No alarms. The black soot around the idle exhaust ports are back. Other than the occasional surging on planning speed it runs and starts fine.
It is back to the shop. Thoughts on issue? ECM, sensor, VST float sticking (Shop said it was in excellent shape and no sediment), or HP Fuel pump?
I ran it for 7 hours straight no issues. Then the surging came back. It runs at 4200-5000 rpms and then all of sudden it surges until it dies or I bring to idle. The first time I thought maybe it was water in the fuel so I drained the racor water filter but gas looked great and I primed the bulb - ran fine for 30 minutes. It happened several other times where I just stopped and shut it off and restarted. Ran fine after restart but 30-40 minutes later it would surge again. This surge is like it is starved for fuel and it is a major drop in rpm – going from 4400-5000 to 1500 rpm or it dies. It later ran fine back to the harbor which was a 2 hour run. No alarms. The black soot around the idle exhaust ports are back. Other than the occasional surging on planning speed it runs and starts fine.
It is back to the shop. Thoughts on issue? ECM, sensor, VST float sticking (Shop said it was in excellent shape and no sediment), or HP Fuel pump?