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Gary Mc · 21-12-2017, 12:28

Hi my experience has been that Yanmars do not typically have or need glow plugs. Mine have started first time, every time in even very cold weather i.e. 0 F.
If it is slow starting, even in fairly warm weather, it is likely time to get your injectors cleaned and set up.

They do generally have a decompression lever, that will reduce the compression on your cylinders, so your starter can get it up to speed easier.

I have never needed it even a 30 year old Yanmar.

Gary

stormalong · 21-12-2017, 12:41

Even if you think you don't need them use them. It makes your engine start sooner therefore reducing load on your starter motor. The starter motor is expensive and, depending on your engine installation may be hard to change.

My engine marinizer (Beta Marine) told be to always use them and my engine starts in an instant.

Anything over 10 seconds of cranking is too much.

chris95040 · 21-12-2017, 12:46

If you are asking this question, you haven't read the operator's manual for your engine.

If you truly want to "make sure I take care of her", I'd start there.

sazarac · 21-12-2017, 13:09

Quote:

Originally Posted by Cool Hand Luke

My Jeanneau Sun Odyssey 409 has a glow switch, as seen on: https://www.yanmar.com/media/global/...tasheet-LR.pdf

I was wondering when I would use it and how do I properly use it. Normally, to turn on the engine, I press the ON/OFF SWITCH briefly and then press and hold the START SWITCH until the engine is running. That's what I did in the Caribbean waters when the weather was warm. Ironically, that's where I purchased the vessel and was never told otherwise.

Now, I'm in Jersey City, New Jersey. It's cold, but the engine starts fine in 40-50 degree Fahrenheit weather. But, what if the weather drops to below 30... what's the best/safest way to start my engine?

My "Anywhere" is my first sailboat and I put my life savings into her and she's my pride and joy... I want to make sure I take care of her for myself, for my family, and... if I ever do decide to sell, which I hopefully won't, then I want to make sure any future owner also has a well-kept engine.

Thank you in advance to all the experienced sailors/mechanics!!

-Lukas

I recommend you read the owners operating manual for your engine.

Techtool · 21-12-2017, 14:52

Push the glow plug button and watch your start engine battery volt meter if it drops a few volts when the button is pushed the plugs are working. Diesels fire on heat of compression. All the time I worked for Volvo the response we were always told to give customers was " on any start below operating temp use the intake heaters ...if at operating temp dont"
Just sayin....

01kiwijohn · 21-12-2017, 15:39

Yanmar is an indirect injection motor so I doubt it has glow plugs. More likely a manifold air heater (Think Hair Dryer. In fact, I've used a 1500 Watt hair dryer to start a few diesels in cold weather. Ether is an absolute last resort).
give it about 10 to 15 secs and then keep it on while cranking, you'll find that she'll light right up, even when the temperature is in the 30's.
You can't really hurt anything by over using the heater.
If you need a manifold heater, try your local John Deere dealer. JD uses a lot of Yanmar's in its smaller tractors and I have found the parts to be a little cheaper there.

Sailorbob8599 · 21-12-2017, 15:39

Quote:

Originally Posted by chris95040

If you are asking this question, you haven't read the operator's manual for your engine.

If you truly want to "make sure I take care of her", I'd start there.

Good comment Chris! ... I was employed as a manufacturer's service representative for two major U.S. corporations for over 35 years. One, a manufacturer of world class heavy equipt; the other, the best known name in the manufacture of commercial trucks.

I cannot count the number of times I've asked that same question not only of new owners, but also service shop management and employees. It's amazing how many people 'who ought to know better', would admit to never having read the owner's manual. It was almost as though some of them deemed it to be 'beneath their dignity' to do so.

I'm not familiar with the marine engine in question, but with new technology like the internet and 'Google', one can research an awful lot of information from manufacturer's, which is exactly where one should acquire the information on a product such as a marine engine, and never rely on an unknown person's 'opinion' because, that is exactly what you will get and not necessarily the information you need.

My first experience with 'glow plugs' was gained when I served as a heavy equipment operator in the British R.A. F. in Germany, during the early '50's. Many of our vehicles of German manufacture used Deutz air cooled engines. They all had glow plugs activated by the ignition switch. First position was the glow plug operation;a red light would ignite on the dash. This would stay activated until it reached fuel flash point at which time, the red light would go off and one could then start the engine.
btw ... Glow plugs can be seen on the exterior of a cylinder head and usually will have a heavy insulated copper strip running from one, to the next cylinder in line.

My mantra is the same as a couple of other respondents to this thread ... ... ... READ THE BOOK; READ THE BOOK; READ THE BOOK. This applies to so many other similar questions of "how; why; when;" ... applicable to mechanical/electrical equipment on your boat.

P.S. ... If you don't think you need to read the owner's manual, who did you think it was intended for?

**Wotname** · 21-12-2017, 16:36

FWIW to those still suggesting the OP should read the manual, please refer to post #8 (and a couple before that)

seabreez · 21-12-2017, 16:37

[QUOTE= Lastly, glow plugs are typically used for as aid for cold weather starting and a rule of thumb would be to switch them on for around 10 to 20 seconds before attempting to start.

They preheat the combustion chamber to ensure faster starting. They are turned off once engine fires and idles smoothly.[/QUOTE]

The glow plugs are just a small pencil type probe in the combustion chamber that all glows red hot, all together (even if the piston is all the way at the bottom of the cylinder). When the injection of atomized fuel is introduced hitting the probe, it is at that time the ignition happens. The glow plugs are in the "off" position when cranking the engine over. That is why you must turn the engine over immediately after the glow plugs are still hot. I understand this is the way all glow engines work. This is a safety in case a person would introduce starting fluid in the intake. Some engines are equipped with a pre-heating element in the air intake, warming the air as it is introduces in the combustion camber (rare) and contrary to glow engines these preheated elements come on to keep the engine at a normal operating temperature.

Frugal · 21-12-2017, 21:03

To check if there are glow plugs or manifold coils fitted and functioning, a quick test is to check if there is a voltage drop on the circuit as you press the glow button.
As either units have a high current draw you should see a faint dimming of your ignition light or a voltage drop if you have a volt meter attached.
Merry Christmas.