Excise amt reducing in J1IIN

D Friends,

I'm struck in the following scenario:

1. Excise amt in Commercial invoice is say e.g. Rs. 254 but when I'm creating its Excise Inv. (J1IIN), then the Excise amt is getting reduced to Rs. 90. If the Excise amt is Rs. 170 in commercial inv. then in J1IIN it is getting reduced to Rs. 60.
2. Means what ever the Excise duty is there in Commercial inv., it is getting reduced in J1IIN. I'm able to save J1IIN but with the reduced Excise.
3. I do not have help of ABAP.

Pl suggest.

Thank you.