Motorcycle Repair: umbrella valve, happy new year, oil leak

Question
g'day Mike, is it nessacery to have the umbrella valve in place and if you run without it, what difference does it make as a few of my mates dont have them installed. thanx. Greg

Answer
The umbrella valve vents air when the bike is running. If they are not there then you vent air out, as well as suck air in as well as dirt if youa re in a dusty condition, which will wear motor parts. Over time it will probably cause a oil leak
Happy new year
Mike