Bummer. It's rare to hear that a new YS 110 would not idle. Both of mine achieved a nice stable idle after running through a 14 oz tank slobbery rich on the bench:



I did have to lean out the low end a little bit to get the engines to idle when they were mounted inverted. I hope you know that counter clockwise on the low end needle valve = lean and clockwise = rich.

I'm getting close on my Spit. I'm waiting for a set of custom pneumatic retracts with 1/2" diameter oleo struts from Century Jet. The wheel wells have been enlarged to take 3-3/4" diameter wheels.