POPPER, The screw is a M3 metric screw. I lost 1 on my buggy 1st run. Went to the local hardware store ( old fashioned with the big wall of screws) and bought a bunch. 9 cents ea. They're on all 4 and I think they hold the engine on too. I think Lowes has the big wall of screws too. I got some extra body clips there too. No paperclips! LOL