I am the shop that assembled this thing. No left over rings. It ran great for a while, and had compression, then I went down the ethanol and carb hole. Once I got that fixed and it was still running good, this happened. Now the fuel pump has puked again. I am resigning myself to another tear down but it seems curious that 2 and 5 are both close in the up and down movement of the crank, and the first fuel pump failed mechanically, the pin wore on the body. In some world, could this be something with the cam shaft? I checked the numbers on the crank and cam shafts for compatibility during the rebuild, but did not mic the lobes
