This is base on http://www.e2mod.com/content/view/196/29/ 

Huge thanks to cherr from motofan.ru for that tutorial!

The Java Heap size on Motorola Linux Phones (E2,E6, A1200 ......) is controlled by the following file:
/ezx_user/download/appwrite/setup/ezx_system.cfg

You can edit it using eKonsole or telnet to your phone, or download it to your pc to edit it. Find the line which says "JavaHeapSize = 4". Now you can change that number from 1 to 6. They corresponds to:
1 - 512 KB
2 - 768 KB
3 - 1024 KB
4 - 2048 KB (default)
5 - 4096 KB
6 - No limit

I have tried on A1200, the option 5 is work. 6 is not work. You can try on your phone.