I'm not sure if I can help you or not, and I can't really see from the pictures, but... We're running pretty much the same setup on a Hangar9 1.20 Edge with a side-mount and Pitts style muffler. I can't see where all your fuel tubing is running, but with the pump DO NOT hook up your muffler pressure line like you would with a non-pumped engine. On our setup we had to turn the pump screw in as far as the manual said before we could get the bubbles out of the fuel line and a solid full flow to the carb. One thing that I noticed in your pictures is the fact that you have the inlet and outlet lines set up vertically, and the manual says to mount the pump with the inlet/outlet nipples horizontally. I know it doesn't look like you have much room inside the cowl to do that, but I would get it as close as possible. Also, while you're changing this, you need to make sure that the breather hole for the pump (90 degrees from the inlet/outlet nipples) is either pointing up, or down, whichever the pump instructions say. And lastly, if it still doesn't run well after you get the pump mounting fixed, you might put the plane on a stand inverted and have a friend hold it, and try starting it with the engine upright. I'm not sure if the OS 1.60 likes being inverted or not. I hope this helps, and you get your plane running soon!!! Good luck! -Grant