Put the dump valve back on and replaced the crankshaft pulley amongst a few other small jobs. Gave it a run and it's only pushing 12psi. I did knock the Amal valve with a spanner a couple of times fairly lightly, but strong enough to bend the plug on top. Could this cause the above issue? But I notice I still have "wastegate chatter" in addition to the dumpvalve opening.

It should be 24psi so it's halved
Obv saph 4x4 cos

Gurus please give me your knowledge

Anything else you need to know?

Dan