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Hi all, I have 3gm30 in my C&C which when cold or simply not run for awhile is difficult to start and requires quite a bit of throttle to get it going. It thens runs a bit rough (5-10 sec) until it seems to "clear out" and then runs good. When started it smokes quite a bit (black) but then stops smoking. Overall a good running motor except when starting up.

Thoughts??

Thanks, Dave M.
 

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3GM is probably much like 2GM. Because it has no glow plugs, mine was reluctant to start from cold until I learned the technique.

With sea water **** CLOSED, throttle CLOSED, crank it on compression for about 5 seconds. OPEN sea water ****, FULL throttle - and with one hand on the throttle to catch it before it over-revs - hit starter. As it fires and accelerates through 1000-1200 rpm, smoothly reduce throttle to a fast idle (about 1100 to 1200 RPM - any less and it will probably stall if it's really cold).

Maybe if the engine has been idle for a while you will want to initially turn it over (with the seacock CLOSED!) with the decompression lever actuated just to circulate the oil. But to get it running, it needs some heat in the cylinders, and the quickest way to get that without glow plugs is to crank it on compression for about 5 seconds before putting in fuel. Personally, I think that just cranking it gets the oil moving enough without the decompression thing being necessary. I only use the decompression lever after an oil change to make sure the filter is primed.

footnote: I see the English word for a valve, starting with 'c' having an 'o' and another 'c' before ending in 'k' is automatically censored to four **** Unbelievable prudery.......
 

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Same engine in my C&C 35/3!
Yanmar recommends a lot of throttle when starting - at least half and possibly more. Back smoke is unburned fuel. Its possible that the injectors are in need of servicing, but if it runs fine otherwise I would not worry about it.
Check out cncphotoalbum.com for C&C specific issues!
Joel
 

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My 3GM30F sometimes does that. I have assumed it gets a little air into the fuel system when it sits for some time. Haven't been able to prove that however. No leaks evident.
 

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If you have followed the troubleshooting steps for the problem, and it is not low compression or injection timing, or one of the other mechanical issues try running the Power Service Diesel Kleen product through it. A lot of times you get some minor injector nozzle buildup that keeps the swirl pattern from being just right until the cylinders heat up a bit, the Power Service will help this a lot.

Just in case you do not have your service manual..

http://www.yanmarmarine.co.uk/pdfs/service_manual/EPB5494.pdf
 

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I have a 2QM15, also without glow plugs. Your starting characteristics seem similar to mine.

Here's my method:

1. Crank for about 5 seconds with throttle closed. This pre-heats the cylinders from compression, but without loading up unburned fuel (which will cause smoking and fuel on the water when it starts).

2. Advance the throttle to full open, still while cranking. As engine begins to catch, pull back on the throttle to avoid high revs. Settle into a moderate idle, and observe oil pressure rise and cooling water flow.

I keep the seacock open for this entire evolution (I don't like running the impeller dry), but be careful of excessive cranking with the seacock open, since you'll eventually fill the exhaust line and muffler with water and it will enter your engine.
 

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If you had a tractor with a yanmar, you would use this LOL

GLOW PLUG (THERMO-START PLUG)

Pretty dangerous on a boat imho.
 

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If you had a tractor with a yanmar, you would use this LOL

GLOW PLUG (THERMO-START PLUG)

Pretty dangerous on a boat imho.
There really is nothing at all wrong with having glow plugs on a boat, most diesels from other manufacturers do have them. Yanmar chose to leave them off on their older models for who knows what reason, however, the newer Yanmar engines have the glow plugs, and no compression release valves. Small diesels under 10 liters generally have them, except for the very small and the very old ones. All automotive diesels currently installed in cars for sale in the US that I know of have them, and I believe that is the way they come worldwide.

Even though you may think having fuel and heat come together in the same place sounds like a bad idea, it is the only way you get combustion, which is kind of important in the internal COMBUSTION engine. The trick is that the combustion stays internal, and the Yanmar glow plug does not risk external combustion any more than any other glow plug system would do.

This is a UNiversal/ Westerbeke pencil type glow plug. All Universal/Westerbeke engines use them, though the type and style vary. Unfortunately I have not seen a way to install glowplugs on the Yanmar Marine Diesels.



Mark
 

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Building a diesel without glow plugs is cheaper than building it with them. And since recreational boaters are cheap and tend to not use their boats in cold weather...It sadly makes good sense to build cheap engines without glow plugs.

It also would make sense to check the options for the engine oil. Most old manuals will spec a single-viscosity oil because motor oils weren't very talented 30 years ago. These days? Odds are you can use a good synthetic, and those are available in multi-viscosity ranges like 0W40 or 0w30 which make cold starts real easy. Much kinder to the engine.
 

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Building a diesel without glow plugs is cheaper than building it with them. And since recreational boaters are cheap and tend to not use their boats in cold weather...It sadly makes good sense to build cheap engines without glow plugs.

It also would make sense to check the options for the engine oil. Most old manuals will spec a single-viscosity oil because motor oils weren't very talented 30 years ago. These days? Odds are you can use a good synthetic, and those are available in multi-viscosity ranges like 0W40 or 0w30 which make cold starts real easy. Much kinder to the engine.
Actually most marine diesels are not Yanmars, and everyone else uses glow plugs. Yanmar chose not to do so, and the cost at time of fabrication would have been miniscule, in fact Yanmar went to glow plugs after the GM series, the YM and JH series and I believe the QM series as well have glow plugs. It was a design flaw, probably due to an engineer not thinking about the fact that not all sailing is done in the tropics LOL.

The flaw is what it is, and the best way to deal with it is to treat the fuel, the tanks, and the entire system and make sure that the engine is well lubricated and maintains good compression. The Yanmar is very ticky about compression being high enough, so a slight loss in compression makes them a total pain in the arse to start when cold. Power Service additives will help this problem tremendously, and help more than you might imagine. Also the Lucas Oil additive which improves all temperature viscosity is worth using.
 

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Hi all, I have 3gm30 in my C&C which when cold or simply not run for awhile is difficult to start and requires quite a bit of throttle to get it going. It thens runs a bit rough (5-10 sec) until it seems to "clear out" and then runs good. When started it smokes quite a bit (black) but then stops smoking. Overall a good running motor except when starting up.

Thoughts??

Thanks, Dave M.
http://www.yanmarmarine.co.uk/pdfs/service_manual/EPB5494.pdf

See page 398 Chapter 13-10 for cold starting procedures
 

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The Yanmar tractor "glow plug" is actually installed in the air intake and makes a small fire.
 

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Mark, I've met plenty of Volvo and Westerbleak [sic] marine diesels, none of which had glow plugs. So it isn't just a Yanmar thing. You know, why increase the cost of the engine by maybe $500-1000 by adding in some equipment that most buyers will never miss not having, when just getting them to upgrade to a diesel at all was such a hard job? (Going back to the A4 days, which really weren't so long ago when we're talking about old boats built in the early 80's.) And yes, i'd expect that the extra machining on the head, the inventory and assembly of the injectors, the added electrical wiring and all, would have to add at least $500 onto the sale price of a boat.

As for oil additives...like religion, feel free to chose your own and believe in it. Modern motor oils are also radically different from what was out there in the 70's or even the early 80's, and if you are buying the right motor oil to begin with, there should be no need to add "Secret sauce".

The first time I did an oil analysis, or I should say the first time I had one done, I was totally baffled to find high molybdenum content. I know what moly can do, I just had no idea the premium oil I was using, had a healthy dose of it already included to do that. Thnk of it as "Purina Engine Chow", the bottle really does have everything your engine needs to have healthy fur and gleaming eyes.
 

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I don't know how much the various "secret sauces" cost, but wouldn't it be simpler to just use synthetic oil in the first place?
As someone with over 25 years of experience in maintaining and repairing diesel engines I recommended the use of Power Service and Lucas Oil Additives, this is because I know a whole lot more about diesel engines than most of you will ever know. These are not "secret sauces" they are tested and proven commercial additives used by companies like J.B. Hunt, Schneider, Swift, Werner, Halliburton, KBR, Nabors, and hundreds of other large companies because it works. Now if you want to listen to someone who is not a diesel mechanic, has zero diesel engines in his shop to be rebuilt, and thinks that most marine diesels do not have glow plugs because he has seen one or two without them, go ahead.

I hate giving advice on here because there will always be some ding a ling who thinks he knows more than someone with literally thousand of hours of training and experience who will come along and tell everyone how the expert and highly trained professional is wrong. I wander if a doctor were telling you that you should take a certain medicine if you wanted to live longer, would you go to a palm reader and take their advice instead? Would you prefer the advice of someone who earns a six figure income because he knows diesel systems, or the advice of a person who sells doughnuts or something for a living?

Do whatever you want with your engine, believe that glow plugs cause fires, or whatever other nonsense you want to believe, but until you have one of these little motors torn down in your shop that someone is paying you to rebuild it might be wise to listen to someone who knows what he is talking about. Try buying some of that "original type"oil sometime, it is not out there because the EPA would not allow the process which was used to make the oil in 1965 today. Secret sauce...yeah.
 

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Hey Mark,

Although you quoted my question, your reply seems directed at the posts of others, rather than mine.

To restate my question using different words, wouldn't synthetic oil be a better choice than mineral oil with an additive?

I could see a fleet operation choosing the mineral oil/additive approach due to cost factors, but for the average sailboat engine, which probably only has an oil change once or twice a year, the extra cost for synthetic oil wouldn't be all that significant.
 

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Hey Mark,

Although you quoted my question, your reply seems directed at the posts of others, rather than mine.

To restate my question using different words, wouldn't synthetic oil be a better choice than mineral oil with an additive?

I could see a fleet operation choosing the mineral oil/additive approach due to cost factors, but for the average sailboat engine, which probably only has an oil change once or twice a year, the extra cost for synthetic oil wouldn't be all that significant.
We do not use mineral oil, we use petroleum based oils with Lucas Oil treatment to help provide an even viscosity at all temperatures. The Lucas helps the oil to adhere to the metal as it should especially when cold starting
and this helps maintain good compression. We add it to synthetics and petroleum normal oils. The thing is that every oil used now needs to have some help, the EPA has made the producers use processes which take away a lot of the lubricating effects of diesel by removing the sulfurs and other things that are supposedly going to keep the motors from polluting as much. Now we have to add stuff to gas and oil and diesel...

The Power Service Diesel Kleen is a fuel polisher, and injection system maintenance product, the Lucas is designed to help maintain the oil in a good lubricating condition, while not allowing it to gum up. Some people call these additives "secret sauces" while real mechanics know that they are maintenance lubricants and additives. Most people do not know that there are bacteria which grow very well in fuel, and you must treat the tank to prevent the growth, which is part of the reason why I use these products as well.
 

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Thanks Mark.

If I understand you correctly, you advocate the use of an oil additive in both synthetic and petroleum based oils. Do you have a position regarding the choice between synthetic or petroleum oil? It's my understanding that sythetic oil inherently possesses many of the advantages you mention (things like stable viscosity, metal affinity, contaminant dispersion, etc.).

With regards to fuel additives, I've seen here and other other threads that you advocate both Lucas and Power Clean. For purposes of lubricity, there is a report floating around that rates "Opti-Lube XPD Diesel Improver" at the top of the heap (actually, the report rates biodiesel at the top for lubricity, but you'd still need a separate additive for cetane, etc.). Any opinion on that product?

Also, you mention biologic contamination. I assume you're referring to the use of biocide in diesel fuel -- but isn't that a separate product? (In other words, Lucas and Power Clean don't contain a biocide, do they)?

Russ
 

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Thanks Mark.

If I understand you correctly, you advocate the use of an oil additive in both synthetic and petroleum based oils. Do you have a position regarding the choice between synthetic or petroleum oil? It's my understanding that sythetic oil inherently possesses many of the advantages you mention (things like stable viscosity, metal affinity, contaminant dispersion, etc.).

With regards to fuel additives, I've seen here and other other threads that you advocate both Lucas and Power Clean. For purposes of lubricity, there is a report floating around that rates "Opti-Lube XPD Diesel Improver" at the top of the heap (actually, the report rates biodiesel at the top for lubricity, but you'd still need a separate additive for cetane, etc.). Any opinion on that product?

Also, you mention biologic contamination. I assume you're referring to the use of biocide in diesel fuel -- but isn't that a separate product? (In other words, Lucas and Power Clean don't contain a biocide, do they)?

Russ
The Power Service brand Diesel Kleen product has a lubricity booster and comes in two formulas, one is a cetane booster the other is just to polish the fuel and clean the system. Power Service brand Bio Kleen is the biocide product they sell, it works very well in conjunction with the other products. The Lucas is what I prefer for the oil, and I have used it for many years. I have used Slick 50, which has the teflon additive in it years ago, but I am not even sure it is still on the market, and while it did everything it was said to do, I just did not really think it was needed most of the time.

I have not tested or used the Opti-Lube product, and have not gotten any service bulletins or notes on it, so I really cannot say anything about it. I will say that Power Service is what I recommend because it is available world wide and is not too pricey. I highly recommend against any use of bio-diesel products in any form in any engine, and can tell you that the stuff is acidic, toxic to motors like you would not believe, and should be banned completely as a fraud and scam. It costs less right now because of subsidies, take them away and it is going to be much more costly than petro diesel. The decrease in fuel mileage already makes it more costly over the long term, add in the injector and cylinder damage and it is highly costly to operate.

On oil, I recommend rotella from shell for diesel engines, the reason being is that synthetics are not as available when cruising, and the life of the oil is not that much greater. In our commercial semi trucks we go 40k miles between oil changes with a filter change at 20k miles, or 30k miles with no filter change. A typical engine lasts about 1 million miles with no rebuild and indefinitely with the rebuilds on our road tractors. The use of synthetics showed us no increase or decrease, the key is routine regular maintenance, good maintenance will give a life of service that will outlast the platform the engine is in, whether it is a truck or a boat.

I do recommend synthetic oils in differentials, transmissions, and other non combustion units. It performs well and has an extended change interval that is markedly longer. Although the synthetic oil manufacturers have said that the change interval in engines can be extended, the cost is not good enough to justify it when you factor in the multiple filter changes that are required when you run extended service periods in a truck engine, which is one of the many reasons I would not run it in my engines.

The science of lubrication has come a long way, but there is a lot of room for improvement, and I would very much like to see EPA made to chunk out the whole urea additive program and reburner setups and be able to go to a much more efficient engine in a two stroke that would reduce particulate by gallon of fuel more than the current methods. The two cycle diesels got twice the fuel mileage at the same horsepower ratings, and could have been improved even more. The four cycle diesels were headed to a point where fuel efficiency was going to be a lot higher too, until the corn growers and others got involved and EPA made us go to the new setups that use urea or a reburner system, and those both dropped fuel economy per gallon by as much as 30%, so in overall per gallon burned particulates you actually see a drop, but in particulates per mile you see an increase of as much as 20% or more due to fuel economy. When you burn more fuel you produce more pollution, it is simple to see, but EPA are simpletons and cannot see it.
 
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