signs an engine is trying to seize.??

hi, i was in the woods today on my yz 125, and all of a sudden, my engine was loosing power, sounded all grargally, and had smoke coming out,, it also reved kinda funny,, and my throttle felt extra easy to turn.... could it be a lean seizure? or maybe my cable was tangled,, or maybe my idle screw was against my slide.. or could it be a drop of water coming thru? i think it was either water, or the idle screw too close to slide... what do you all think?

thanks. ps,, it cleared up after about 10 seconds,and ran fine.

this is a new top end, new piston, ring, and just got it ported for bottom end power, and cylinder was polished out...it was strange,, whatever it was..