Originally Posted by
xspower
Turn the HSN to flush with the body of the assembly. Then turn the LSN so that it is just starting to show about 2 mm worth of "needle" in the housing past the outside of the control lever that is on the slide it self. Start the engine. Go ahead and get the HSN set properly with the power and then work with the LSN. You are backwards the engine when it hangs high and stays high with no drop is lean on the bottom. The trick here is that you have no power on top. That is telling me you are way to lean on the top also. So work with the top then the bottom. You should get back to where you need to be. If this fails then test the carb for leaks. But I would think you would see fuel leaking if it was leaking. The Picco engine has a small "sweet spot" for the top needle when you get there you will find that the smallest turn to the lean side will cause the engine to loose power and the bottom end to fall off as well. I think this is where you are at. The top needle to lean. If you need any other info feel free to PM. Hope it helps
XS is spot on. If this does not work for you, try changing the pipe. On a few occasions, I have seen guys chasing the tune on this engine When it was in fact the pipe that was causing the problem. What happens is the exhaust gasket tears and lodges in the pipe, blocking the flow and you could change needle settings all day without finding it. BTW, you will not be able to get the piece of gasket out without cutting the pipe. I have seen this a few times and we got the gasket out by cutting the pipe open.
Let's hope XS is righjt or you will need a new pipe