Oily Liquid Coming From Exhaust

So you have oily droplets coming from your Yanmar's exhaust? What is it and is it a sign of a serious problem?

Typically what you are seeing is caused by the soot from the diesel exhaust mixing with condensation or rain getting in the muffler. This is really common on just about every tractor with an open top exhaust. Yanmar diesels, like all diesels, are naturally 'sooty' and that soot, when mixed with moisture, blows out those

greasy little droplets. 

So how to fix? The first step is to put a can or something over the exhaust pipe when you are not using the tractor.  You can get little flapper caps that go on the top of the exhaust pipe but they aren't really waterproof. They will block heavy rain from pouring straight in but won't keep things dry.

Another option - we actually have developed our own muffler to help prevent that in two ways- 1- it has a drain hole in the bottom to help drain out any moisture or rain that might make its way into the muffler and it also, 2- can pivot so you can point the muffler horizontally forward and keep rain out of the muffler and blow the smoke forward away from you. You can see our new muffler in this link.  

A leaking valve stem seal in the head could cause oil to leak out into the muffler also but this happens in an area where there is extreme heat and that oil is almost instantly burned and would produce relatively heavy smoke. If you don't have heavy smoke then this is not likely your problem.