Wasnt cleaning, but bros mate Noddy,
(Nickname), was push starting our Greeves 250 go-cart. Didnt know his hand was on the chain guard, ouch! His thumbs was OK after quite a bit of surgery though.
Soz, cleaning/service, stupidest thing was the contraptions we cobbled together to get car engines out, thinking about it, then working underneath. Luckily nothing happened there!!
Oh, yeah, bros got me sticking my figer in a spark plug cap, while he turned it over, that hurt!
Older, wiser now, I hope, LOL.