Peter are you using a teflon coupler in the YS 4 cycle?
Matt
ORIGINAL: PeterP
James,
I am currently flying the Alliance with exactly the same equipment as you. I found a lot of noise is coming from my pipe coupler which is slightly loose. I am looking at other options at the moment. When I apply a little teflon tape around these fittings to make things tight again the model suddenly goes silent again . A flight or 2 later as the tape wears away the noise comes back.
Peter