[lurkingknight]

the semi trigger on the p90 is like a v2/3 setup, there's a shuttle that gets pulled back by the trigger that pulls a little metal block between 2 metal prongs to close a circuit and cycle the gun... when the sector cycles, the cam on it moves the cutoff arm and flips up the shuttle and it resets because it's spring loaded.

Your problem here is that most likely the shuttle is getting caught in the prongs and the cutoff level doesn't have the force to pop it free. You need to pry the prongs open just a tiny bit to make it just tight enough that it will cup the block, but not so tight the block wedges in.

The other issue of a non working semi in a p90 is a worn cutoff lever.


The auto trigger is activated when the trigger is pulled back all the way. The front trigger shuttled would have already reset forward, but there's another 2 sets of contacts that get closed by the bottom of the trigger assembly so that will fire the gun continuously. If you're finding yourself having to pull back really hard to get it to fire full auto, the 2 prongs need to be bent forward ever so slightly to meet the trigger block sooner.

It could also be possible that the front trigger block is being held so tightly and that your rear trigger isn't even completing a circuit so the cutoff lever takes a few whacks to get the block to reset in the semi trigger.

if the semi contacts are too tight, a p90 will keep firing till that block resets, full auto, trigger down or not.