I have a Komatsu PC50UU it starts only on full throttle but cranking time is excessive then will run until you try and use hydraulics or idle down. Machine was operating fine yesterday no problems ? Any ideas ?
i have a pc50uu-1. it was in pretty rough shape when i got it. Not sure if you have the pc50uu-1 or -2 as they have different engines. I installed an inline electric fuel pump from summit supply on my machine right underneath the tank. this helped starting A LOT! I was skeptical of the mechanical diaphragm style fuel pump and just assumed it was probably cracked or leaking...hope it helps a little
If you've got the PC50UU-1, there's a hand primer on the injection pump. Reach over the engine and it's a lever on the right side of the injection pump looking into the engine bay from the rear. It's a little hard to locate the first time, but it's there. It presses straight down and you should feel some resistance. If I prime mine prior to starting, (only if it's been sitting for a day or so) it will start instantly. If I don't, it will require cranking for a couple of minutes, in spurts, to start. I give mine 5-6 pumps and only have to do it the first time it's started for the day. the dying problem sounds like a fuel line or filter plugged. If you get it started and can keep it running by intermittently stroking the primer, you're starving for fuel somewhere. Starting on full throttle I would think was normal. That's what I've always done. Greg