my son just got a 2015 420 Honda he has around 150 km on it, he called me tonight and said his air breather box is full of oil, any input would be great.THANKS

 

Is there a crankcase/gearbox/tranny vent hose going to the air box that puked? What was the quad doing just before he found this condition? Look at all hoses to air box to narrow it down, I can't think of anything that would back up through the carb but then again, anything is possible

 

Either he has filled the crankcase far to full of oil or there is a very serious engine fault, bad rings, head gasket blown into the oil gallery etc. If the air box was full of fuel, it would be a bad injector, I didn't think this was possible but someone posted on here that their air box had filled with fuel on an old model 420.

It is just possible the bike got tipped onto it's side during transit to the dealer, being tied down in a crate, there would be no damage to the bike, but oil could leak from crankcase to air box.

 

It is common for manufacturers to route the crankcase breather vent to the airbox. That is probably where the oil came from. Hopefully he just overfilled it and the excess pressure blew some back through the breather. Otherwise it is probably time to check out Honda's warranty services because merryman is likely on the right track.

 

To much oil, a tip over and steep hill ridding can cause it also.