Nyemach in Mesa Grande. Cuevas places the stress on the first syllable here, causing the spelling to be modified to nyímech. Based on the Mesa Grande spelling, the stress is expected to be on the last syllable: short vowels in the last syllable (excluding any grammatical suffixes) followed by a consonant will receive the word's stress. Additionally, the shwa (e) as the one in nyemach, can never receive the stress.
It remains to be confirmed if other speakers indeed pronounce the word as nyemách.
Examples of use include 'enyaa nyemach "me too", maa nyemach "you too", which can be shortened to 'enyaamech and maamech.