i get home from work and my step mom tells me "well i was mowing and it ran out of gas, i filled it back up, topped up the oil, but then it wont start" so i go out and take a look...looks fine, nothing OBVIOUSLY wrong with it. it has spark and fuel...but its pulling too easy. no compression, this is bad as i just put on a new head gasket.
so i pull it around front and pull the shroud and head. the intake valve is open. i spin the crank...it stays open. i think "f@$k bent valve f@$k f@$k f@$k" so i spin the valve....it spins true...wtf, not bent?....ok, maybe its just stuck? so i tap it with a screw driver hand.e. doesnt go back down....i'm getting a lil confused....so i pry it up with the blade of the screw driver...
out falls a tiny screw, about 2 milimeters long and about one wide with an inset hex head. :) it was jamming the valve open preventing compression.
HOW THE HELL DID IT GET IN THERE???!!! the air filter was on the whole time she was mowing. i'm thinking it HAD to have come loose from in the carb. so i need to pull that apart tomorrow and look for where it came from. but i have a good idea. i think its the screw that holds the butterfly to the shaft. :)