Hi all, I sure hope someone can steer me in the right direction with this issue.
Here is some background: 2008, F60TLR Yamaha Four-stroke, with 478 hours. All filters, spark plugs, lubrication, etc have just been replaced. Problem started out of the blue with no pre-existing hints something was going wrong. Engine ran for about an hour, smooth as glass just as it has since it was new, then I throttled down to minimum speed for several minutes while I chatted with someone alongside me, then the engine suddenly sputtered, choked up and died. It would start as soon as the key was turned on, sputter a few times and then instantly die. My buddy towed me home. I suspected a fuel problem so I removed the "IN" hose from the mechanical fuel pump and squeezed the fuel line bulb. Gas spurted out of the hose with each squeeze. I reconnected that hose and removed the "OUT" hose from that fuel pump and turned the engine over with the key. Not a drop of fuel came out of the fuel pump, so I ordered a new one. The new pump arrived and I replaced it and then preformed the same test and fuel spurted out of the "OUT" port on the new pump. However, once everything was connected the engine still would not run for more than a few seconds before sputtering and dying. So I rigged my tire filler gauge to just read pressure and tested it on a tire, it read just fine. Then I attached it to the Schrader valve above the fuel injection rail and cranked the engine over with the key and starter. Not a single PSI registered, no pressure, so I ordered a replacement fuel injection pump. It arrived with a new VST filter and I installed the new kit. (That was an interesting project!!) Once everything was back together I tested the engine and it started right up and ran fine. I figured, OK, I'd fixed the problem, I had a hard time believing that both fuel pumps could die at the same time, but as we all know, "stuff" happens!
So yesterday I take the boat out for sea trials. Engine started right up and I got underway slowly, increasing speed by 2,000 rpms every minute or so until I was running at WOT. Ran great. I slowed down to around 4,200 rpms and ran for 45 minutes, then slowed down to minimum headway speed again to talk with my buddy in his boat and after a few minutes the engine sputtered, choked up and died. Once again it would start right up, then sputter and die a few seconds later. He towed me home again! (I owe him big time!) When we got back to the launch site, I tied the boat to the wharf and tried the engine, it started and ran in gear for several minutes then sputtered, choked up and died. I took it home and tried it again, this time it ran for less time (maybe two minutes) and then died.
Anybody got any idea what I should test or check out next? I'm totally puzzled.
Thanks to all that offer assistance, I am truly lost.
Roger B
Here is some background: 2008, F60TLR Yamaha Four-stroke, with 478 hours. All filters, spark plugs, lubrication, etc have just been replaced. Problem started out of the blue with no pre-existing hints something was going wrong. Engine ran for about an hour, smooth as glass just as it has since it was new, then I throttled down to minimum speed for several minutes while I chatted with someone alongside me, then the engine suddenly sputtered, choked up and died. It would start as soon as the key was turned on, sputter a few times and then instantly die. My buddy towed me home. I suspected a fuel problem so I removed the "IN" hose from the mechanical fuel pump and squeezed the fuel line bulb. Gas spurted out of the hose with each squeeze. I reconnected that hose and removed the "OUT" hose from that fuel pump and turned the engine over with the key. Not a drop of fuel came out of the fuel pump, so I ordered a new one. The new pump arrived and I replaced it and then preformed the same test and fuel spurted out of the "OUT" port on the new pump. However, once everything was connected the engine still would not run for more than a few seconds before sputtering and dying. So I rigged my tire filler gauge to just read pressure and tested it on a tire, it read just fine. Then I attached it to the Schrader valve above the fuel injection rail and cranked the engine over with the key and starter. Not a single PSI registered, no pressure, so I ordered a replacement fuel injection pump. It arrived with a new VST filter and I installed the new kit. (That was an interesting project!!) Once everything was back together I tested the engine and it started right up and ran fine. I figured, OK, I'd fixed the problem, I had a hard time believing that both fuel pumps could die at the same time, but as we all know, "stuff" happens!
So yesterday I take the boat out for sea trials. Engine started right up and I got underway slowly, increasing speed by 2,000 rpms every minute or so until I was running at WOT. Ran great. I slowed down to around 4,200 rpms and ran for 45 minutes, then slowed down to minimum headway speed again to talk with my buddy in his boat and after a few minutes the engine sputtered, choked up and died. Once again it would start right up, then sputter and die a few seconds later. He towed me home again! (I owe him big time!) When we got back to the launch site, I tied the boat to the wharf and tried the engine, it started and ran in gear for several minutes then sputtered, choked up and died. I took it home and tried it again, this time it ran for less time (maybe two minutes) and then died.
Anybody got any idea what I should test or check out next? I'm totally puzzled.
Thanks to all that offer assistance, I am truly lost.
Roger B