I have B&M (dry) AND Marshall (liquid filled) fuel pressure gauges.
On the Marshall gauge there's a plug in the hole where the fuel would go into the gauge but there's a catch, the plug has little ridges in it so it doesn't fully plug the hole. It is slotted for a screwdriver and the hole itself is threaded.
On the B&M gauge there's just a hole.
I can only assume Marshall added this piece to prevent small debris from entering before anyone tried to install it but can anyone verify this? I'm pretty sure it has to stay removed in order to work properly.
Linear Mode
