Having push started both, the direct drives are alot easier especially with the metal bumper. A short push then drop and the 100s are away.
With the decompression valve you don’t pick up the back but have to push for alot longer. Nine times out of ten you will see one of the dad’s that are struggling need an extra hand from one of the other parents/mechanics to get it going.
This might be a stupid question, but can’t you just disengage the decompression valve and start it like an oldschool 100cc?
That’s what I would do, but I guess unless you know you can why would you?
I also think the modern rear bumpers aren’t great for run and bump for a solo. But it’s the FIA, not a lot of thought out with regard to karting.