I don't know where to begin...
I had a problem with my Century trigger group in my Romanian SAR-1 AK-47. It would occasionally double fire. The disconnector, if released very very slowly, would release the hammer which would slip past the sear. In otherwords, either the disconnector or the sear wasn't getting enough length on the hammer. This isn't uncommon with low-quality Century trigger groups and the most recommended solution is getting a Tapco G2 trigger group to replace it.
Today I received and installed my Tapco G2 single hook trigger group in my AK-47. The trigger pull was extremely short. I mean, as soon as you START pulling it, CLICK! It is also fairly light. Anyway, it wasn't a safe combination by any means.
So it turns out the trigger group wasn't fitting quite perfectly in the trigger well (which had rounded corners). I fixed this by rounding off the corners of the base of the G2 trigger with a file. The trigger group now sits perfectly in the trigger well and doesn't touch any of the sides. Because the trigger could rotate forward more, this also fixed the issue with the length of pull. The trigger pull became longer.
However, now I have the following problem: if I let go of the trigger (to cancel a shot for example) it does not go all the way forward again. Apparently there is a lot of friction on the sear and the hammer. I think the problem has something to do with the G2 sear because I swapped parts and it doesn't matter which hammer I use (G2 or original Century), the G2 sear continues to get stuck up. On the otherhand, the Century sear runs smoothly with both the G2 and Century hammers.
What should I do? Needless to say I am very frustrated. I've been spending the last 3 hours trying to fix this. Filing edges, swapping out parts, nothing seems to work.
Please help me!