My 9yr old had his first outing on the Rev 50 yesterday and did really well with the clutch. I dropped the bike through the forks 1" and rolled the bars back slightly to make it easier for turns. Just need to bring the long clutch lever closer to the bars and it will be spot on for him.
I let him slowly release the clutch while I was on the bike a couple of times (no throttle at all) and then he had a go on a big flat field. I jogged alongside him for a minute and then left him to it, he was stood up and buzzing around with a huge grin on his face all afternoon.
He crashed into a fence and trapped his thumb right at the end of the day which put a bit of a dampener on it but he's still really keen to get out on it again next week.
"I parked it Dad!"
By the way, he started off on the Oset 12.5" and then the bigger 16" version which he recently grew out of. Great little bikes to get going on, anywhere, any time...