bendyone
Well-known member
I could start my 1GM10 on my own by having a bit of string round the decompression lever held open by standing on the end, when turning as fast as I could lift my foot and off it went.
Hand cranking a 1GM10 - can anyone do it?
- Thread starter jimmynoboat
- Start date
cliffordpope
New member
I have just experimented starting mine by hand and succeeded without much difficulty.
My experience, for what it's worth, is that it is a waste of effort trying to build up revs with the decompression lever operated. The flywheel has no momentum, so the only worthwhile effort is what goes into turning it over against actual compression.
My method;
Turn the engine about half a dozen times with the lever operated, just to pump in some fuel.
Let the lever close, position the crank so that it is on it's way up on a compression stroke, then with 2 hands on the handle give it one good heave over the compression.
ie use the time-honoured method of starting any engine, petrol or diesel - flick it smartly over a single compression.
Leave the stop cock closed until it is running, just in case it backfires. Mine didn't, it started instantly.
My experience, for what it's worth, is that it is a waste of effort trying to build up revs with the decompression lever operated. The flywheel has no momentum, so the only worthwhile effort is what goes into turning it over against actual compression.
My method;
Turn the engine about half a dozen times with the lever operated, just to pump in some fuel.
Let the lever close, position the crank so that it is on it's way up on a compression stroke, then with 2 hands on the handle give it one good heave over the compression.
ie use the time-honoured method of starting any engine, petrol or diesel - flick it smartly over a single compression.
Leave the stop cock closed until it is running, just in case it backfires. Mine didn't, it started instantly.
Evadne
Active member
I would add: Warmth helps, hand starting in the early spring is a lot harder than this time of year. My 1GM (almost the same) always needed full to 3/4 throttle to start until I changed to using yellow diesel. Now it starts more quickly, on tickover. Probably starts by hand better as well but it's not something I practice.
robp
Active member
Blowing warm air into the air intake just prior to starting helps a lot. Which unfortunately this comment doesn't - unless you've got enough power for a hairdryer or lots of huff!
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C
catalac08
Guest
I had a 2qm15, so theoretically easier than a single cylinder 10hp - I tried everything , both decompresors lifted,crank like mad and drop only one decompressor lever. Would just stop dead. Never succeeded over several years. The previous owner was a policeman about 7ft tall and built like the proverbial brick outhouse and he never succeeded either. I think the crank web instead of a flywheel just dies not build up enough inertia to enable hand starting on these Yanmars.
What I did do was operate the starter whilst hand cranking and then managed to start the engine on a number of occasions when the battery was too flat to turn the engine over on its own. This needs 2 people to do this but worth a try.
What I did do was operate the starter whilst hand cranking and then managed to start the engine on a number of occasions when the battery was too flat to turn the engine over on its own. This needs 2 people to do this but worth a try.
Ubergeekian
Active member
You, sir, must have arms like a gorilla - and a lot better access to the handle than I have. I couldn't get it over a single compression by brute force.
ducked
Member
How about using an "easy start" spray?
On my old car I used a bit of butane as a choke substitute, reasoning that it wouldn't wash the cylinders like the choke (which I think I had somehow broken anyway) and actually had a gas line plumbed in to the air intake for a while.
This might be a bit chancier on a boat where any that escaped the engine would end up in the bilge.
Somewhere I've seen reference to a diesel engine that had some arrangement for burning diesel fuel in the intake, to provide heat. I think there was some kind of wick and electrical heating/ignition element (but I suppose if you had electricity for that you wouldnt be hand starting). Sounds like a glow plug but it wasn't. Maybe it just created fuel vapour, but I THINK the fuel was actually burned outside the cylinder.
However, the AI guyzmo that works for Google says "Yes, burning diesel fuel in the intake manifold is a method to preheat a diesel engine and improve its performance and cold start", so with that kind of support I must be wrong
Butane blowtorch to preheat, say, a bit of rebar, and/or a wire mesh in the intake path?
Heating the injector (and precombustion chamber) would make it like a hot-bulb or semi-diesel, many of which were officially started with a blowtorch (or electrically, or even pyrotechnically heated) as standard procedure, but I suppose that might be damaging.
Here's some WW2 advice from the RAF
How to start a Norwegian fishing boat – and other useful information………
"To find out if the motor is warm enough for starting put an ordinary safety match against the head without striking it. If it lights immediately the motor is hot enough. Make it a rule never to put out the blow lamp before you are certain that the engine is running. steadily. It should always be kept handy in case of engine stoppage”
Starting
And running.
On my old car I used a bit of butane as a choke substitute, reasoning that it wouldn't wash the cylinders like the choke (which I think I had somehow broken anyway) and actually had a gas line plumbed in to the air intake for a while.
This might be a bit chancier on a boat where any that escaped the engine would end up in the bilge.
Somewhere I've seen reference to a diesel engine that had some arrangement for burning diesel fuel in the intake, to provide heat. I think there was some kind of wick and electrical heating/ignition element (but I suppose if you had electricity for that you wouldnt be hand starting). Sounds like a glow plug but it wasn't. Maybe it just created fuel vapour, but I THINK the fuel was actually burned outside the cylinder.
However, the AI guyzmo that works for Google says "Yes, burning diesel fuel in the intake manifold is a method to preheat a diesel engine and improve its performance and cold start", so with that kind of support I must be wrong
Butane blowtorch to preheat, say, a bit of rebar, and/or a wire mesh in the intake path?
Heating the injector (and precombustion chamber) would make it like a hot-bulb or semi-diesel, many of which were officially started with a blowtorch (or electrically, or even pyrotechnically heated) as standard procedure, but I suppose that might be damaging.
Here's some WW2 advice from the RAF
How to start a Norwegian fishing boat – and other useful information………
"To find out if the motor is warm enough for starting put an ordinary safety match against the head without striking it. If it lights immediately the motor is hot enough. Make it a rule never to put out the blow lamp before you are certain that the engine is running. steadily. It should always be kept handy in case of engine stoppage”
Starting
And running.
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oldbloke
Well-known member
I never managed to start mine when the battery was completely flat but on a couple of occasions succeeded with my wife pressing the starter and using the last dregs of electricity as I dropped the decompressor
scottie
Well-known member
When the 1gm first appeared we tried to hand start no luck on a bench in the workshop
ducked
Member
Might a rope start work, if you could bolt a suitable flange to the front of the flywheel?
If so, it would be especially useful to me, since the boat didn't come with a starting handle, and I believe they are quite expensive for what they are.
If so, it would be especially useful to me, since the boat didn't come with a starting handle, and I believe they are quite expensive for what they are.
scottie
Well-known member
No such thing
It a crank handle
ducked
Member
Theres no such thing as a rope? Well, I’m suggesting/speculating that there could be.
scottie
Well-known member
I am simply saying that not even yanmar refers to a starting handle other options are possible but not included. In yanmar media thus implying they leave it to your imagination
ducked
Member
Thats a bit confused/confusing. Yanmar certainly refer to a starting handle. To quote the owners handbook, under "Cranking The Engine Manually" we have...""
"5. Slide the starter handle (Figure 8, (1)) on the starter shaft (Figure 8, (1)),
align the groove and pin, and turn the engine over about 10 times"
Perhaps you meant to say "starting rope"?
Thats for Manual Cranking, to get the oil distributed, and they say
"When performing engine break-in or if the engine has not been used for a long period of time, engine oil will not be distributed to
all the operating parts. Using the engine in this condition will lead to seizure."
For Manual Starting
Turn the handle vigorously. When engine rotation is rapid, return the decompression handle to the RUN
position.
So they aren't recommending the "Single compression pounce", though it makes sense with a low mass flywheel, and would probably suit a starting rope .
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scottie
Well-known member
Come on it’s Christmas
andsarkit
Well-known member
My 1GM10 starts really easily and in my youth I have hand started it just to see if I could. Unless you are built like a gorilla you will need a second person to operate the decompressor lever. In my old age I doubt I could start it any longer so always ensure I have enough left in the batteries.
I still have a scar above my eye from trying to start a Lister concrete mixer when the very substantial handle came off the shaft.
I still have a scar above my eye from trying to start a Lister concrete mixer when the very substantial handle came off the shaft.
Buck Turgidson
Well-known member
Ive started my 2qm15 3 times by hand and failed about 10 times. Just did it to see if I could and then thought it would be good to do it every now and then for practice. I no longer bother due to too much effort and not enough success. I figure in an emergency the adrenaline would assist the process.
Poignard
Well-known member
Until I installed a second battery I frequently had to start my BUKH engine by hand after a few nights without shore power and cabin lights and the radio on had flattened the only battery.
It wasn't a difficult engine to start as the BUKH has a heavy flywheel.
A heater in the air intake made it easier.
It wasn't a difficult engine to start as the BUKH has a heavy flywheel.
A heater in the air intake made it easier.
Halo
Well-known member
I managed to manually start my boat engine after I changed the oil to Mobil 1. (0W60 ) oil. The oil makes a lot of difference to the effort required to turn the engine over and the lower the first number the better. It’s also much easier when it’s warm. So my advice is go to the thinnest oil. I know that this will be synthetic which some regard as a herassy but it worked for me for years and being able to start is a fundamental requirement!
Stemar
Well-known member
It all sounds to me like a lot of faff - and potentially dangerous faff at that. Far simpler to have a dedicated starter battery, isolated from the domestic system, with a VSR to charge it. That way, it's highly unlikely you'll ever need to hand start your engine. Yes, my first car had a starting handle, and my Dad made sure I knew how to use it effectively and safely, but I don't think I ever used it in anger, and that car was only a year or two younger than I was, back in the 60s