If the fuel is leaking internally (into the engine) it can be the PV. It can also be the main body or the metering block isn't flat. Or both. I've had them where I had to remove the boosters, fit the main body into the mill, indicate it in and cut .040 off to get it flat. I've heard of some being off .060 but I can't verify that.
If it's leaking externally it's probably that the MB isn't flat.
Sometimes the $850.00 for a BLP B4X is worth every penny.
