hard starting Yanmar

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Steve O.

I have a Yanmar 2GM20 that starts hard when cold. I have to crank it for a full minute before it fires, then it blows out a big cloud of smoke and a little oil out of the exhaust. After it fires up it seems to run OK. Is this a symptom of something I should have a mechanic look at?
 
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Wayne Estabrooks

Yes!

Low compression might be a cause of your hard starting problem. Do you have glow plugs? If you do the circuit or switch to them or the plugs themselves could be faulty. If you haven't already destroyed your starter motor this is a sure way to overheat it and then you will have more of a problem than just a hard starting engine. You should never crank more than 15 seconds without letting the starter cool.
 
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Justin Wolfe

If you haven't already

When cold do you have the throttle ALL THE WAY FORWARD when you crank the starter? We had this problem on several Yanmars. Problem is gone with the throttle forward. Just keep your hand on the throttle so as soon as the engine starts firing you can back off the RPMs to your warm up RPM.
 
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Steve O.

thanks guys

Thanks Wayne and Justin for your advice. I haven't been pushing the throttle all the way forward, because I never had to on my last boat which had the same engine, and it started right up every time. But I guess they're all different. And I also haven't been running the starter constant for 1 minute, I meant that it takes over a minute to start, using 15 second bursts. My fault for the confusion there.
 
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Bob E.

Same problem

I have the same problem with the same engine, except maybe a little worse, in a 1989 H30G. More smoke, longer cranking, and several restarts required. This engine starts OK in warm weather. The Yanmar 2GM20F does not have glow plugs, but someone told me that if you give it full throttle during starting, the injector timing is changed to assist cold starting. A question -- if the engine can develop full power when warmed up (7 knots at 3400 RPM), could there still be a problem with low compression? I would assume that low compression would reduce engine power. True or not?
 
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Don Riha

Possible injector Problem

I have a 89 Hunter 30 that developed the same problem you described. It was a cracked O-ring at the injector which did not allow ignition until it was warmed up from all the cranking. Once started it ran fine and no problems on a hot restart. The second mechanic pinpointed it from the description, the first replaced the filter and ignored my calls when it didn't work. Get a mechanic that knows the Yanmar. Good luck.
 
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Andy

Ditto-2GM20F

Same problem too. Thought I'd tried all the tricks, attended a diesel workshop, had a mechanic service it, read all the manuals, but after 2 years, I'm still reading with interest whenever someone writes about how to start it when cold. Yes, it starts. But, rarely without difficulty. Could it just be the design of the 2GM20F, am I expecting too much, or do they actually start well for some people?
 
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Gene

Try this for starting

I have a 1985 Hunter 34 with the 3 cylinder Yanmar. It seemed to be hard starting this season and a mechanic found that the fuel line connections were loose. Also, I found that I have to give it LOTS of throttle when starting then it starts all the time. Be sure to cut back on the throttle quickly though when it starts.
 
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Don Riha

Comment on "Ditto"

My engine always starts immediately if the throttle is at 3/4 open, even after winter storage. If hard starting have the injectors pulled and checked. Comments are interesting since I suffered from the same problem several years ago and once corrected it has been fine. Great to push the button and BAM, it's running. Good Luck.
 
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ken

yanmar hard to start

have some one check the compression if its below 380 it6 will be hard to start
 
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