Slow Starting Engine

Cotillion

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I have a Yanmar 1gm. It is difficult to start 1st time and belches smoke before eventually catching. Having started it once it will behave impeccably for the rest of the day, starting virtually on the button. Is it a cold thing? If anyone else out there has had a similar problem I would appreciate your advice.

P.S I removed the air filter so it's not that.

Kim /forums/images/graemlins/confused.gif
 

dickh

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I'm not familiar with the 1GM, but does it have a glow/heater plug for easy starting? If it has burnt out this may be your problem.
 

PIGLETSDREAM

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The 1GM doesn't have a glow plug and should start first time. Ours I start by hand, first time. Check you have no air getting into the fuel, bleed screw on top of pump. Check injector is sealed correctly, although if you take it out, get it serviced. If the engine is quite old, it could be that it is getting blocked in the exhaust, ours certainly was, they also develop small pin pricks in the exhaust cooling pipe that allow water into the head. Have a look at the Yanmar forum here http://www.yanmarhelp.com there will have been loads on 1GMs, I know cos I posted them last year. Then there is the famous bent con rods caused by water compression, I hope it is not that cos it becomes expensive then, details on the web site. Whilst not a fully paid up member of the oily rag club, I have replaced the head gasket and re-ground the valves on ours so have a dangerous amount of a little knowledge. I am sure other wiser forum members will offer advice to contrast mine /forums/images/graemlins/smile.gif
 

cindersailor

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I have been through this problem with my 1gm and still have not entirely sorted it. It is probably 23 years old and I put my problem down to low compression and replaced the con rod which was very slightly bent - most likely due to a water lock sometime before I bought it, and the rings. This improved things a bit but cold starting was still not a pleasure, in reality it probably needs a rebore. Wanting to avoid this job for as long as possible I have now fitted a glow plug (any old one from the scrap yard should be OK) into the air filter unit (having removed the filter which I now do without - I just replaced it with a fine metal gauze to prevent big lumps being sucked into the engine). 30 seconds heating before starting has largely solved the cold starting issue. The glow plug needs to be supplied via a relay as it draws quite a large current. The large amounts of smoke (white?) you are seeing is just the unburnt diesel that has been injected during your starting attempts.

Another thing that has helped is to put a switch in the alternator field wire so that I can start without the alternator loading the engine. Once it picks up and I throw the switch the load on the engine to replace the starting current is quite significant and would certainly cause problems with starting. I should add that my alternator is not the standard Hitachi 35A one, but a 60A one from a car, hence the serios need for this mod. Send me a pm if you would like more info on my glowplug set up.

One further thing, mine will only start from cold if I use full throttle. Also,, depending on your exhaust set, up it may be sensible to keep the water seacock off until the engine has started if it is taking a long time as you risk filling the exhaust with water and then the cylinder - hence the bent con-rod!
 

Gunfleet

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They are peculiar. Mine will only start with little throttle and takes quite a few turns before it fancies it. If you do write some notes abt your glow plug set up I'd love a copy by pm too.
 

Evadne

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My 1983-vintage 1GM wouldn't start very well, then I got water in the bore and it seized (a problem with the anti syphon valve). After having the injector replaced, the pre-combustion chamber cleaned out and the head skimmed it was much better. Then (don't ask, its embarrassing, and a long story) I had to have both fuel pumps replaced and the injector serviced again due to salt water damage. It now starts on the second "donk". Cold starting (i.e. afloat) needs full throttle but on Saturday, ashore, it started on the second "donk" in neutral. I was quite chuffed.
I would get the injector serviced as a first off, they do wear and are critical to starting. Then I'd suspect the diaphragm on the lift pump. Obviously, you will have cleaned all the lines and filters first.

PS she's still got the same exhaust pipe as was fitted in 1983, so I wouldn't leap to the conclusion that it is at fault, although another known fault is cracking of the exhaust manifold elbow itself, which you should definitely check for carefully as well.

Dave
 

Lakesailor

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Diesels need good compression to start, relying on compresssion to burn the fuel. If the rings or bores are worn or bizzarly the valve guides worn (not centralising the valve on it's seat) you'll have trouble. After you've pumped some oil around gaps close up and it gets compression. My bet is you need a rebuild.
On the other hand, I hope I'm wrong.
 

Evadne

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I'd forgotten about compression, I've rebuilt so many bits of the engine for different reasons that I'd forgotten that I replaced the rings as well. Its not a difficult or expensive job once the engine is off its mountings. I know it definitely doesn't start at all if the rings are cemented into the piston with salt and diesel varnish!!
 
G

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Stuck or worn rings ...

This is so common that many older engines could be stripped and this problem found.

Using easy-start / drawing in extra diesel by full throttle etc. etc. - are all solutions to sealing the rings enough to get that vital compression and ignition.

I don't have a Yanmar - but my Perkins is EXACTLY the same and the one before it etc. etc.
 

Lakesailor

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Re: Stuck or worn rings ...

Easy Start and other such things (lighter gas, petrol etc) may start the motor but tend to wash oil from the bores at the very time you need some lubrication. Brings on the rebore (or liners) a bit more quickly.
 
G

Guest

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Re: Stuck or worn rings ...

I was commenting - not advocating .....

Funny thing is though ... the old wives tale about use of easy-start making an engine NEED easy start to start ... is rubbish .... my old 4-99 was started on ES for near 30 years .... never had the cold-start system fitted by previous owners ...... I fitted it and the engine started on the cold-start without ES without problem.

Trouble is with many people - myself included till I started to be more careful - most spray TOO MUCH ES into the intake .... in fact a tiny well directed squirt is better and less potential damage.
 

Heckler

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Re: Stuck or worn rings ...

nigel
i thought you were old, well oldish, (you are only as old as the girl you feel) and wise!
ES messes engines up cause it explodes rather than burns and busts piston rings or squashes piston ring lands and traps the rings so making it harder to start and needs more ES etc. hence old wives tale of engines getting adicted. octane ratings which you know all about come into play.
stu
 
G

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Octane ?? or Cetane ????

I know of many engines - tractors etc. when I was a lad ... plus of course own boat engines that have had a quick jot of ES .... they still start without ..... it's only occasional use that I have resorted now.

Thye mani problem is the amount that many people spray into intake .... some I have seen nearly emptying the can !!! That I believe is really damaging.
 
A

Anonymous

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Re: Octane ?? or Cetane ????

Nigel, maybe you can explain something that has puzzled me for some years....some diesels have glowplugs which you energise for twenty or thirty seconds before cranking, and some don't. With those that don't, provided I follow the manufacturer's recommended starting technique, all the engines I have ever used start immediately. With those that require a pre-heat, if you cut it short or don't bother, they don't start (maybe not surprisingly).

So why do some manufacturers design diesel engines with glow plugs and some don't??? Incidentally, I haven't used a starting fluid on a diesel in my life and I have never had one fail to start. I used to use them on an old two stroke Francis Barnett motorcycle, but that is another story!
 
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