With all cards in play
Sacrifice Myr Retriever with Krark-Clan Ironworks (2 mana)
Sacrifice Scrap Trawler (4)
With Scrap Trawler's ability, return Myr Retriever to your hand
Cast Myr Retriever, Genesis Chamber's ability will create a token (2)
Sacrifice Myr Retriever (4) and return Scrap Trawler to your hand
Cast Scrap Trawler (1) and sacrifice it (3) to return Myr Retriever to your hand and create another token.
Repeat the process, sacrificing the tokens, for infinite mana
With infinite mana you have infinite tokens.