Hand-crank 2GM

[lockie]

The book says you can, but I can't .
Any Charles Atlas types out there who can resist the temptation to kick sand in my face, and help me?

9-stone weakling

[cbsura]

Did you open the compression levers?

[lockie]

Yes of course I opened the decompressors.

But (a) how do us folks who don't have 3 arms close the decompressor whilst still cranking and (b) how do we summon enough strength to get through the compression stroke? Is it actually humanly possible?

I'm also considering making a foot switch that I can temporarily connect to the start circuit. This would allow me to use my foot to engage the starter, leaving both hands free to crank. That way, maybe me and the almost-flat batteries together might just do the trick.

Would using that nasty start spray stuff help (remember we're talking desperation here).

lockie

[JesperWe]

Originally Posted by lockie

Yes of course I opened the decompressors.

But (a) how do us folks who don't have 3 arms close the decompressor whilst still cranking and (b) how do we summon enough strength to get through the compression stroke? Is it actually humanly possible?

I'm also considering making a foot switch that I can temporarily connect to the start circuit. This would allow me to use my foot to engage the starter, leaving both hands free to crank. That way, maybe me and the almost-flat batteries together might just do the trick.

Would using that nasty start spray stuff help (remember we're talking desperation here).

lockie

I never managed to do it by hand, but what did save me a couple of time was opening the decompressor, and run the starter to rev up the engine, and then close the valve wile the engine was spinning. Even a rather flat battery had enough energy to turn it quicker than by hand, when the valve was open.

[Wotname]

I am pretty weak and lightweight but I have managed it a couple of times providing someone else was there to drop the decompression lever at the right moment. I only drop one cylinder while leaving the other decompressed until the first one fires.

I haven't achieved it single handed yet but sometimes think about setting up a foot operated string to pop the decompression lever down.

[lockie]

A couple of good ideas there, which I reckon are worth pursuing, because one of these days, my batteries will be flat,or the starter will fail, and I'll be up excrement creek without a paddle.

Or like the other day, when I was exhausted after a really hard couple of days, with 25 miles to get to my home port against a head wind. That's either a boring but comfortable 5-hour motor sail, or a pretty taxing 10 hours or more of beating. No problem years ago, but a bit much for an old fart.

I imagine something like a small 2 cylinder (like the 2GM) is about the limit for hand starting, so I guess that's why there's not that much interest in it.

lockie

[Wotname]

Originally Posted by lockie

............

I imagine something like a small 2 cylinder (like the 2GM) is about the limit for hand starting, so I guess that's why there's not that much interest in it.

lockie

Hmm... not so sure, what makes hand starting easier is mass, particularly flywheel mass. Bigger flywheel, easier hand start

So bigger engine (ie more cylinders), more rotating mass so maybe easier to hand start - assuming you start on one cylinder only at first.

This is just a half ar**d guess; any experience out there???

[SkiprJohn]

It is not easy and I had to do it while bouncing in 9 foot waves one day when my friend's boat drug it's mooring and was attacking another boat with it's bowsprit. His batteries were nearly flat.
Face the engine and have everything clear of where your arms will swing. Open the compression levers (don't swing them too far because they will start to close again if they are over the top). Do a couple of slow turns to get your muscles used to the swing. Now give it all you've got and put down one compression release handle as quickly as you can then get the other one down when the first one fires and helps the engine spin. If you just can't get it done then start training your muscles for the time you have to do it the next time.
I don't think there is a trick to it. It becomes brute force.
Watch those compression release handle because if you go too far over the top they will start to close again (that's twice I said that just to make a point).
kind regards,

[roverhi]

I hand started my Volvo MD2b for almost 10 years, even started a MD3b to prove it could be done. Secret was the big flywheel on these engines. Use the compression release, crank like crazy to get it spinning as fast as I could, and drop the compression release on one cylinder. Engine would fire first time, every time on the one cylinder. Would then drop the release on the second cylinder at my leasure.

Suspect the Yanmar doesn't have enough mass in the flywheel to make hand starting easy. Too bad the hand crank attachment is blocked by the alternator/water pump belt or I'd try it on my 3GM30f just to see how much fun it is.

Cranking with the starter engaged in the case of a low battery would make it easier. Also, if you are sailing, cranking it with the engine in gear makes turning over the engine a lot easier. Surprizing how much force there is from water pressure on the prop.

[NCboatrx]

The GM series Yanmar engines are extremely hard to start with a hand crank because the flywheel is so light.

On other engines such as the old Volvo and Sabb and Farymann diesels, when you had some cranking speed up and flipped the decrompresor lever back to the run position, the weight of the heavy flywheel alone turned the engine over past TDC which made for a fairly easy hand crank start.

All of this assumes that the boatbuilder actually allowed enough room for one to work the hand crank and valve lifter levers.

[charliehows]

yeah unless you're a 250 pound weightlifter you wont hand start a 2gm - even then you probably wont succeed, the flywheel is way too light to overcome the compression stroke.

[SkiprJohn]

Sorry I responded to this earlier and made it sound doable. I was speaking of an old 2 cyl. Volvo and an Albin. They can be hand started.

I don't have experience with the 2GM.

kind regards,

[keyspc]

Ether is a killer of rings and valves. had a gm i was going to put in this boat but it only ran ten min before froze up.

make sure all fuel lines are bled of air and have pressure. spray WD4o if you must then open decomp valves (take the bolt thinge that joins the off!) full throttle then crank like a mofo and trick for mine was KEEP cranking!! pop first lever eng goes pomp pomp pomp dont give up swing it! when it sounds like its running allmost then kick over other valve and keep cranking it gets easer as motor revs.
BTW shoulder surgery is a bitch!!

[lockie]

Originally Posted by keyspc

spray WD4o if you must

Interesting - why the WD40?

[keyspc]

Originally Posted by lockie

Interesting - why the WD40?

same princeable as ether but doesn't wash all lube off cylinder wall and intake valves.

have heard of some spraying fuel in intake but i never had luck with that.

EDIT: just noticed your in melbourne, i'm at Eua Gallie if you need a hand PM me and we'll meet up. got kids on weekends though