I may have a Yeiser in one of my maternal threads. My Green/Greene line goes back from my maternal great-grandfather. Charles Green 1668-1721 married Margaret Yeiser 1675-1723 in Maryland or Pennsylvania. She died in Huntingdon County, PA, as probably did Charles. Charles Green was born in England. Actually, I don't know for sure at this point if Charles is in my own Green line.
Yeiser is apparently an Americanization of a German name, such as Jeiser or similar. J is pronounced like Y in German. You can get more information on this match by browsing at Ancestry.com.