When playing with the combustion fan you need to be very careful. If too much air is induced into the stove with a less then perfect draft, you will pressurize the stove. Gas will leak from everywhere. Also when adding a bigger (cfm) fan many things take place, some not good. If a bigger fan is added, this will cause the coal on the grate to levitate. In turn if the coal levitates (gets lighter) as it goes across the grate, it will move easier and inturn use more coal. More coal coming across the grate at a faster rate means one thing, incomplete burn. There is one correst answer to 2 pages of rice only, that's RICE ONLY.
Hope this helped,