Chris,
A shot in the dark here...........This is presuming you have removed the oil metering pump and are premixing 2 cycle oil in the fuel..............If
so did you block the oil feed orifice from the front (rear in your ship) iron to the front cover...........This oriface will bleed off some pressure (I do not
know how much) if not blocked and if the metering pump drive gear is also removed will probably bleed off even more..............Tracy might be able
to shed more educated light on this theory............FWIW
Kelly Troyer