07-12-17, 11:42 PM
(Apologies Disorderlypunk, I didn’t notice you’d already made the point about the drain hole.)
The innards of the silencer are mild steel and rot through at the base so the gases can blow out of the gap around the pipe where it enters the stainless can. You may be able to bodge it by squishing in as much high temperature silicone sealant as possible. I got a couple of extra years life out of mine that way.
Having said that, I doubt it’s the cause of your running issue which sounds much more like an electrical problem to me.