I'm not sure where to go from here. Help is appreciated. 2003 Yamaha F225 stalls out and dies, sometimes at idle sometimes faster. Indeed, it has sputtered out at 600 RPMs or 4000RPMs. Problem was VERY sporadic initially (like once every 10 trips) and is terrible. I believe it's a fuel starvation problem, so here is what we have done:
1. LP replaced by Yamaha mechanic (his initial diagnoses). Did a 40 mile after this without any problems. Then issue popped up a week later.
2. Ran off an auxiliary tank with new good gas and still stalled out
3. Fuel rail pressure is measure at a constant 40PSI (guage does not have numbers small enough to tell if 40 or 42). When the engine does, fuel rail pressure drops to zero.
4. LP cycles on and off at idle like it should. Indeed, one time the engine died with the pump running and another time it died in between the pump running.
5. Checked the check valves in the fuel lines. They only let air go one way.
6. New fuel filters and check the fuel water separator on the outboard which was clean.
7. This is the interesting part Cleaned VST filter which was about 50 percent clogged and there was plenty of debris in the VST tank. The HP pump's wires were shotty and didn't seem plugged in well at all. Rebuilt the connections and got them plugged in better.
Since cleaning the VST and fixing the HP connections, haven't had the issue of sputtering out. Though the boat has only run a few hours at idle and low RPMs.
Does anyone have suggestions of other stuff I need to rule out? I ordered a new HP anyway which I'll plop in this week.
Also, given the nature of this happening at various RPMs and fuel rail pressure being okay right until the sputtering/stalling, my mind goes to electrical and those connections. Any opinions on whether this could be the culprit?
Any help is so so so appreciated. Thanks!!!
1. LP replaced by Yamaha mechanic (his initial diagnoses). Did a 40 mile after this without any problems. Then issue popped up a week later.
2. Ran off an auxiliary tank with new good gas and still stalled out
3. Fuel rail pressure is measure at a constant 40PSI (guage does not have numbers small enough to tell if 40 or 42). When the engine does, fuel rail pressure drops to zero.
4. LP cycles on and off at idle like it should. Indeed, one time the engine died with the pump running and another time it died in between the pump running.
5. Checked the check valves in the fuel lines. They only let air go one way.
6. New fuel filters and check the fuel water separator on the outboard which was clean.
7. This is the interesting part Cleaned VST filter which was about 50 percent clogged and there was plenty of debris in the VST tank. The HP pump's wires were shotty and didn't seem plugged in well at all. Rebuilt the connections and got them plugged in better.
Since cleaning the VST and fixing the HP connections, haven't had the issue of sputtering out. Though the boat has only run a few hours at idle and low RPMs.
Does anyone have suggestions of other stuff I need to rule out? I ordered a new HP anyway which I'll plop in this week.
Also, given the nature of this happening at various RPMs and fuel rail pressure being okay right until the sputtering/stalling, my mind goes to electrical and those connections. Any opinions on whether this could be the culprit?
Any help is so so so appreciated. Thanks!!!
