Yanmar 2GM20 Starting Problems

[scottb34300]

Hi,

I have a Yanmar 2GM20 Saildrive. It was new in 2000 and has done approx. 100hrs. I know that its winter, but starting the engine seems to be a strugle. I have a new 105ah battery, designed for both domestic and starting use, so that shouldn't be a problem. I do not have a pre-heat facility on the engine.

I have to put the trottle to approx. 3/4 full, before the engine roars into life, spluttering a lot of white smoke out of the exahust. Even at this level of throttle, it takes several attempts (about 3 - 5) of holding the start button for around 8 seconds a time.

Considering I have a new battery and the engine is fairly new, with few hours, shouldn't it start easier?

Any suggestions on how to start it more effectively, or what, if anything, the problem could be?

PS: I purchased the boat second hand in October '03, and I have always had the same problem.

<hr width=100% size=1>Scott.

 

[longjohnsadler]

Subjective, non-technical reply, but I too have a 2GM20 (a bit older) and use full throttle and it takes many seconds (15?) to catch, with a fair bit of white smoke.
I'm sure others will give you technical hints, but I was told this was fairly normal for a 2GM, and its been regularly serviced.

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[bigmart]

I used to have a 2GM20F in my last boat. It was always slow to start & required a lot of Battery power to spin it over. Exellent engine once running though.

Martin

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[Heckler]

a diesel engine should start easily, if it doesnt something is wrong. the white smoke is unburned diesel that has been injected into the cylinder that eventually partly combusts when the engine begins to start.
dont know this particular engine but nearly every diesel that i have come across in my long life around them has had a cold start device fitted.
are you sure that there is not a cold start device fitted or procedure to go thru?
stu


<hr width=100% size=1>http://www.beneteau-owners-association.org.uk

 

[snowleopard]

no, the yanmar gm series does not have any form of preheat. it relies on lots of throttle. in winter 3/4, in summer a bit less.

my 3gms likewise need a lot of throttle but have always started inside 3-4 secs, even now after 1500 hours.

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[paulrossall]

I have a Yanmar 2GM 20 which has now done 1100 hours, it is ten years old. I put throttle on full to start in winter and just hold the starter button down until it starts, which does not take more than 10 seconds. I have very thick wire from my batteries to the starter and earth so I do not have a problem with voltage drop which means the engine gets turned over fast which aids a quick start. My fuel tank is probably unusual in that the fuel level is normally above the engine so the fuel side of the engine is under pressure, not waiting for the fuel pump to suck fuel through, although some-one who knows more than me will probably say that should not effect engine starting.
If I were you I would put a volt meter on the + terminal of the starter motor, and then a suitable earth and try to start and see what happens to the voltage. Dont put the + leed on the battery because that will not tell you if you have a voltage drop at the starter. If it drops dramatically then I would look at the wiring to see if it is substantial enough for the job. Also do it again with the + lead at the battery because maybee the battery is not man enough for the job.
However I would guess your problem is you are not giving it enough throttle to start it. My engine blows all sorts of smoke out the exhaust on starting, but soon settles down. Heater plugs are not fitted to these engines apart from some which are used up near the Artic Circle, from what I have read. This is a good web site for asking questions about Yanmar engines and it also tell about installation and service etc. <A target="_blank" HREF=http://yanmarhelp.com>http://yanmarhelp.com</A> Good luck.Paul

<hr width=100% size=1>" there is nothing-absolutely nothing-half so much worth doing as simply messing about in boats".

 

[Heckler]

aha
in that case he has a problem.
lack of fuel due to a slight air leak, lo compression, or drippy injectors.
stu

<hr width=100% size=1>http://www.beneteau-owners-association.org.uk

 

[timevans2000]

Stu,

I have a 3 cylinder version of this engine. Starts on the button, even in winter. Does need lots of throttle though. I doubt it will be a compression problem as the engine is very low hours. Mine has done thousands of hours and a strip down this winter revealed no wear.
Likely problem will be injectors or an air leak. If you hear the engine catch on one cylinder then eventually on the other, then after a minute or 2 of running there is no smoke from the exhaust, I would guess it has an air leak. If you are getting smoke then there could be a dodgy injector.



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[dulcibella]

My rule with a 2GM20 was to start with full throttle when cold and no throttle when warm. I only had difficulty starting if I used an in-between setting.

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