This is not a mod, but a technique that was passed on to me from yanico on another forum. He got it from a Russian forum he was browsing. This technique really changes the trigger feel & operation on the IZH-53M.
First, crack open the barrel. While the barrel is open pull the trigger (nothing will happen). Then load the pellet, close the barrel and test out the new feel of the trigger. It is like a 2 stage trigger now and it works good and helps with accuracy.
Now, go give it a try and see what you think. After all, doesn't cost a thing!
Bartman