Hi all. I'm suffering from a bit of ignition system drama and I was wondering if anyone else had come across anything similar. At about 4500rpm under load the engine will not proceed, doesn't die but it won't rev any higher, like a rev limiter almost. At the same time the tach shoots down to about half the actual rpm. The rpm that it happens at and the severity of the mis changes but it's always there if you rev it high enough under load. It's fine without load and runs like a top otherwise. I swapped the coil with a spare I've got to no avail, my current thinking is ignition module or a wiring issue. Anything thoughts?