Blue-Smoking Yanmar

[mike d.]

is the motor actually coming up to temperature (raw water cooled around 160, fresh water cooled 180+) if a diesel does not come up to temp you will blueish smoke from the exhaust because of unburned fuel. once the fuel and motor heat up you get complete combustion and the condition disappears. if motor does not heat up you can get your condition. the other thing is your thermostat might be stuck open and cooling the block to much

[Chief Engineer]

Got a thank you from wsvoboda....He filled the oil to the proper level and blue smoke disappeared.

I have seen a lot of overfilled yanmars over the years

[Chief Engineer]

Says blue smoke returned....If Previous owner only ran it at the dock at idle the cyliders are probably glazed.

Google Diesel Engine Glaze Cylinder.

[wsvoboda]

My thermostat is a 170 degree I checked it it works fine and coolant circulates good throughout the engine. Going to resurch the glazing part

[r.furborough]

Overcoming glazed cylinders ultimately requires the removal of the cylinder head and having the honed with a glaze-buster, ideally replacing the piston rings is also a good idea. However, before getting into this try getting the engine upto temperature and then running it hard for a couple of hours, during this time back off the throttle to slow the boat and then accellerate hard upto hull speed, do this frequently. This will increase the cylinder pressures and potentially get the piston rings freed up and doing the job they designed for. It may work for you if the glazing is not too bad.

[wsvoboda]

I have ran the throttle up and got at best 3000 RPM's but I only did this for a minute at a time. The engine runs great I usually run it at 2200 RPM,s and have done this for 12 miles. Still smokes, I ran it up at the dock in nuteral to 3400 RPM's and backed her down, I did this 3 to 4 times and got some black soot in the water but the blue smoke always come back, I idle the engine after a long run at the dock. This is the 12 mile run the last time I went out. It took at least 5 minutes of idling before the smoke went away. I have always been told to idle the engine after a long run to cool it down before pulling the fuel cut off, so I have always been religious about doing the cool down cycle. What do you think about the 50/50 deai with marvel mystery oil and the 15/40 oil to break the glaze?

[never monday]

what oil is in the engine?
what year was the engine built approx?

[wsvoboda]

The only oil I have ever used since I bought the boat is 15/40 Delno A chevron Diesel Oil, Engine number is E23813 and the engine family is XYDXM095P3N, Do not know how to read a vin number on the Yanmars, just Harleys.

[never monday]

Originally Posted by wsvoboda

The only oil I have ever used since I bought the boat is 15/40 Delno A chevron Diesel Oil, Engine number is E23813 and the engine family is XYDXM095P3N, Do not know how to read a vin number on the Yanmars, just Harleys.

so this is a newer Yanmar? about when was it installed in the boat?

[wsvoboda]

so this is a newer Yanmar? about when was it installed in the boat?

My best guiess is around 1998 or 99, It was installed in the bay area and motored down to moss Landing, The owner of the boat who installed the motor sold the boat to another fella who used the boat for a live-a-board for 3 years and as far as I know never sailed the boat, just started the engine once a month at the dock, I purchased the boat in sep 2004 and it was in the yards for 18 moonths for refit and replanking, the boat was splashed in august of 2006 and I have been motoring and sailing her ever since. Oil consumtion is so low I hardley even noyice on the dipstick after 50 hours. Would still like to try the hard motor run you spoke of earlier, waiting for the rain to stop.. I do not have an anolog temperture gage to watch the temp on while doing this proceedure, only the alarm that came with the control panel.

[never monday]

consider one of these


from the small oil loss. I'd consider valve seal.

[H.Wiley]

Can't help w/the smoke. However, FYI-WOT as speced in the owners manual is to be obtained at WOT IN GEAR & moving, no sails & ur normal load-fuel, water, gear, people etc-; NOT in neutral or not in gear tied to dock. If u not obtain that WOT spec the problem is either the engine or the prop(to much PITCH), assuming bottom clean. Critical with a displacement sail hull is that u not trying to push the boat at more than hull speed with an oversized prop for the hull/weight/engine combination;or u will get smoke. Having read a recent thread w/ Yanmar Dsl, after owner spent many $ & much advice, a compression test was finally conducted & the problem diagnosed correctly. Any engine, when the solution is not obvious:START with a compression test-u can take that advice to the bank!
HWWIII