950 Ultra XP tuning on 500"

... A friend of mine has a PS 1000cfm We took a closer at it yesterday to compare the old to the new. We found the tune is almost identical except his is now square jetted and has the PV plugged. If you look closely down in to the main body, it looks as though there are 4 tubes coming from the idle circuit.... Anyone know for certain what they are?

20191027_122028.jpg

20191027_122124.jpg

20191027_122128.jpg

20191027_122044.jpg