I recently used my patern plane after it had sat around for a while.
The YS160 was running fine when i used it last. It's basically new.
The fuel system uses a header tank. There is a check valve fitted on the vent, and the filters are new (one on vent, one on delivery).
I run 30% coolpower blue

- At first i had alot of trouble starting the engine, and when it ran it was lean.
- It ran fine at about 2.75-3 turns out for one flights and then on the second the glow plug fell out, grrrr.
- After the plug was replaced it ran again like this for one more flight, and then went Rich!

- When i got home I found it wasn't sucking fuel very well. I flushed the filters, reg, and fuel lines, but did not disasseble the tank or engine
- I returned the neddle to two turns out
- The engine started easy and ran like this, but surged at idle.

- I pulled the tank out and found the clunk had corroded. I cleaned this and fitted new fuel lines.

- I tried running it again and it started fine.
- It was a little rich at two turns but the transition from low was good.
- After warming up i tried to get the engine to idle. It went low enough in RPM (low enough to stop), but was surging again
- At any other throtle position the engine was fine, it would just slightly surge around idle.
- I seem to need more throtle trim than last to stop it from stopping at low throtle.

- I pulled the regulator off and cleaned it. It seemed to be clean, and the ports were clear etc. I don't think there was a problem there?
- I have not adjust the reg, but up untill now the engine was good.
- I am yet to run it again, but i don't think i have found the problem just yet.

Any sugestions on why the idle is surging, but fine when the revs pick up?
Is something gumed up due to it sitting around?
Something dried up and is leaking?

I have posted on the YS page, but no luck so far.