i installed a PM61 exhaust into my brand new gilera runner ST 125. As soon as it was fitted and bike started up, I was getting a strange noise, almost like when you blow up a balloon and let the air out slowly. It starts and stops, it's defo not coming from any part of the exhaust. So what could this be? Nothing was hit or damaged while exhaust was being changed. I've rode the bike about 7/8miles hoping it'll stop but it's continued throughout. Someone mentioned to me, it might be the breather hose from the air box, is this possible?
