those are air correction jets. they stop overfueling in the higher rev range
the jetting your running sounds very small for a 1.6L I'm running
140 mains 160secs
150 main air correction jets and 195 secs air correction
50 pri 55 sec idle jets
thats for a tickled 4k
go down to autobarn and buy a autometer air fuel gauge for $150. buy a 02 bung from ebay. get it welded in your exhaust and do your own tuning like me and mr altezzaclub are doing