View Full Version : Oil in exhaust

jeff leininger
06-16-2007, 05:21 PM
"When I left our slip this AM, I noticed oil coming out w/ the raw water exhaust on my 2GM20. Doesn't happen in neutral and gets worse as load increases. Didn't see any H20 on dip stick. Help?"

06-19-2007, 10:32 AM
"Hi Jeff, what do you mean about oil? Vast slicks?
oil levels are good? and what are you running your engine rpm in gear and under way. How old is your engine? hrs?
Is your engine factory fresh water cooled?"

06-19-2007, 07:20 PM
Our yanmar is 22 yrs old. Hours unknown. It is raw water cooled. The previous owner had the motor overhauled 4 yrs ago. The oil leak is quite noticable although probably not "vast".
There is no tach on the motor so not sure about rpm. I had changed the oil on Memorial weekend and it ran fine on our weekend overnite. Oil level is good (full). I recently replaced our 3 fixed blade prop with a feathering prop (Kiwi).
I'm wondering if this put extra strain on the motor resulting in a blown gasket somewhere? I haven't seen any water on the dip stick and when I removed the head block zinc, I didn't see oil in the water. Any thoughts?"

06-20-2007, 08:12 AM
"I would would install tachometer, It consists of the tach head and the sender. A must if you want to motorsail. This engine is designed to run under load at 3000 RPM. Top is 3600 RPM under load. This gives you an indication of what the prop is doing. If you run lower RPM the cylinders will glaze and you will get blow by. ie hone and new piston rings. All filters & lube oil should be changed once a season. Fall time. Valves be adjusted cold to .008 Also if you have a goose neck exhaust elbow, remove and clean. These restrict with carbon especially when you run at low RPM. If you do not know your running RPM it can cause you grief. Where are you located?"

06-23-2007, 10:10 AM
Sorry for delayed response. I do change all filters once a season. Oil usually twice. I spoke w/ a Yanmar mechanic the other day and he also suggested removing the exhaust elbow (my next step) I will take your advice & install a tach. We sail on the Chesapeake Bay near Annapolis. Thanks for the advice. Will keep posted on progress.