I guess you're talking about me, tIANchi!

Yup, this ones got me stumped. Even got to the point where I couldn't stop the engine until I closed the fuel line with pliers. Wierd. But absolutely no midrange at all. I've been researching here for a week, which is why I didn't post myself, didn't want to bother ya'll with yet another "YS tuning problems" post.

I've been through it again today. I drew a schematic of the regulator and fuel system to see exactly how it works, then I physically checked the various functions, all is well. Tank held pressure for 24 hours. Carby is clean. 'O' rings, seals and gaskets all hold pressure. And yes Dave, regulator body was the right way around. Fuel is Cool Power 25% heli fuel with 20% oil.

For the next attempt I've set the regulator screw flush with the housing, the low speed needle flush at 2 3/4 turns, high speed at 1 1/2 turns. I've set the throttle barrel stop screw so the butterfly is just where it closes completely. Did I miss anything? Let's see if I can get this sucker to play ball.

I'll try to be a good boy and post back when there's something to say.

Cheers from the Barfly.