Well good news ^^
I think I figured out how to edit the zenny amount in the saves.
First you need a hex editor.
I recommed HxD Link:
http://mh-nexus.de/en/hxd/Also idk if it will work on 4.1 but it works on 4.0.1
First thing you need is 2 saves.
One with a lower amount of zenny that the other by 100 zenny.
I used one with 4650 and the other with 4750.
You open both files with HxD and use the "Compare" option in analyze tab.
If you have just a 100 zenny difference. The hex value should be in 1 byte so it shouldnt have any bytes changed around it. Try to change the differences if you have more than one difference(that matches this description) found.
Once you've found that byte it will be the hundreds' byte like for example my value was 4650 so the byte represented the "6".
The byte to the left is the thousands the one to the right is the hundreds and so on. Once you get into the 10k 100k etc. repeat the method to find the value.
I think that's all. If you don't seem to understand something just reply here.
I would be glad if you would share this method on other sites you are on.(I have some personal issues with the game's owner)
Also don't forget to give me credit for this ^^