# Starting your engine on "dead" batteries



## capta

I was going through a locker on the boat full of "stuff" today, trying to clean out some of that junk we boaters collect as we go through life, and I found four US dimes (a 10 cent piece for those unfamiliar with the term dime), neatly wrapped and shiny new.
For those of you who do not have a compression release on your diesels (propulsion or genset) here is an old engineer's trick that may one day save your bacon.
I put this here because having "dead" batteries could put your boat in danger.
When you find yourself with "dead" batteries, you should stop cranking *immediately*. Next, take off the valve cover and insert one thin dime (and only a dime if you do not want the possibility that the pistons will hit the valves) between the rocker arm and the exhaust valve stem. This will essentially release all compression and what power is left in your batteries should be able to turn the engine over fairly easily.
As the engine turns over, pull out one dime (in the proper firing order) using needle nose pliers and she should begin to run on that one cylinder, perhaps still requiring a bit of help from the starter. As you continue to remove dimes in the correct firing order, your engine should run on 2 or 3 cylinders well enough to get all the dimes out and be running on all cylinders.
Without a valve cover there is obviously going to be quite a bit of oil squirting out, but what's a bit of clean up compared to what could happen if you can't get your engine started?
I hope this will help at least one of you out one day.


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## colemj

That's a great shade-tree trick - I hadn't heard it before. 

I have a $50 lithium jump pack the size of my hand and only a bit thicker. I've used it to jump 5 dead SUV's now and it turns them right over immediately. Haven't tried it on our boat's engine, but it is kept around just in case. Also doubles as a backup charger for phones/tablets if all power should be lost. It will do 10 phone charges.

It's also a good idea to have an emergency parallel switch to bring the house bank to the battery.

Mark


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## hpeer

I carry some jumper cables. Farmer simple.

The dime solution makes some sense. I suppose you could do something similar with some aluminum foil folded over a few times.


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## Barquito

...or you could pull that string that raises those big white floppy things... and sail. I kid.


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## mbianka

I think firing up the Honda 2000 generator to either charge the batteries or jump assist them. Would be faster and cleaner way to get things started. A wayward dime bouncing around the rocker arms seems like it might do some damage.


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## Minnewaska

Cool trick. Sure sounds messy, but a great hack.

I have a switch that will bring house batteries power to the main starter. Thankfully, I've never needed it. I also have a set of jumper cables aboard. I've used them twice in as many years, as my generator start battery is not on a charger. It only charges from the generator itself, which doesn't run often enough. Eventually, I plan to start the generator from the same battery as the main, it's just been low on the list. I could put a battery combiner between the two, but one start for both engines seems like a simpler idea.


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## capta

Guys, obviously this is not something you'd do if you had other options. Anyone who had other options would be nuts to do this.


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## skipmac

Another trick that I used once. If you have two 12V batteries that still have a little charge but not enough to crank the engine, temporarily wire them in series to get 24V. Even almost dead batteries will spin the engine quite fast.

The brief time you do this shouldn't hurt the starter but I would turn off everything else 12V. Also might want to disable the alternator as you will have to disconnect the batteries to wire them back to 12V once the engine is cranked. This probably won't work with modern common rail engines since they need power to run and will shut down as soon as you disconnect the batteries.


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## skipmac

One of the things I liked about my old Volvo MD-17C. It has compression release levers so you could do this trick without the dimes or the mess.

So how come no one puts levers on engines anymore?


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## SVTatia

capta said:


> ... Next, take off the valve cover and insert one thin dime (and only a dime if you do not want the possibility that the pistons will hit the valves) between the rocker arm and the exhaust valve stem....


Great hack Capta, thanks for sharing.
I just wonder if it would work with a Canadian dime... but given the exchange rate nowadays prolly not.:crying


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## oldfurr

"I have a $50 lithium jump pack the size of my hand and only a bit thicker." So does everyone else obviously.
"I carry some jumper cables. Farmer simple." Well thanks jeebus you always have friends with batteries within a jumper cable length.
"I think firing up the Honda 2000 generator to either charge the batteries or jump assist them." The hell? Really? Really? THIS strikes you as a useful comment on the matter of an emergency compression release hack?


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## capta

SVTatia said:


> Great hack Capta, thanks for sharing.
> I just wonder if it would work with a Canadian dime... but given the exchange rate nowadays prolly not.:crying


Now that's funny! I needed a laugh right now, thanks.


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## thvl1

It has compression release levers so you could do this trick without the dimes or the mess.

So how come no one puts levers on engines anymore?


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## Minnewaska

oldfurr said:


> ...."I carry some jumper cables. Farmer simple." Well thanks jeebus you always have friends with batteries within a jumper cable length.......


Most cruising boats have a separate house bank and starter battery, in my case separate main and generator starts too, which jumpers can reach between. It's a pretty cheap and less messy hack for a dead starter battery, but the OP's hack was cool.

I think the post was supposed to be funny, otherwise, I have to wonder how one becomes so "get off my lawn" crotchety to be intolerant of alternative suggestions to a thread titled "Starting your engine on "dead" batteries".


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## hpeer

Mine,

That was a far better and more understanding reply than the one I had in mind. Thanks for being a better person than me.


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## oldfurr

An old trick for getting a start out of "dead" flooded lead acid batteries that have failed out due to low temperatures is to "bootstrap" them. This entails shorting out the battery for about 10 seconds to supposedly warm up the electrolyte in immediate contact with the plates sufficiently to allow the battery to provide the power to crank the engine. It is usually done by attaching jumper cables as normal to the failed out battery and shorting out the other end of the jumpers well away from the possible flammable out gassing of the battery. I suspect it might work with AGM batteries but have never done it or heard of anyone doing it with them, I have no idea what the results would be with gel cells and would in my ignorance expect unfortunate consequences if lithium batteries were subjected to this sort of abuse, BMSs tend to bewilder me still and I would not want to risk damaging the system that is a lithium battery. 
If anyone has real world experience with tricks or hacks for kick or hand cranking boat engines to life I'd like to hear about it, and also ideas on how to do that on an engine that no longer has a starting handle crank on hand.
As to such, at best, fatuous recommendations as in the case of having dead batteries to A). DUH... have a charged battery or B). DUH... charge your battery, feel free to get off the lawn.


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## colemj

oldfurr said:


> if lithium batteries were subjected to this sort of abuse, BMSs tend to bewilder me still and I would not want to risk damaging the system that is a lithium battery.


The thing with lithium batteries is by the time they go too low to start an engine, they are completely drained of power and cannot be Mcgyvered in any way to get them to release more. They really do go to the last drop.

Mark


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## hpeer

> If anyone has real world experience with tricks or hacks for kick or hand cranking boat engines to life I'd like to hear about it, and also ideas on how to do that on an engine that no longer has a starting handle crank on hand.


I have no "real world" experience with these but I have seen these spring loaded starters for sale.

A quick google search brings up this.

https://www.springstarter.com/#

https://www.ipu.co.uk/products/spring-starters/

https://www.atlanticdiesel.com/pdfs/KinetecoBrochure.pdf

It seems that if you have the spring start OR the electric start. Although it seems it is possible, from the starter point of view, to have BOTH starters installed at one time. Apparently the power to the electric starter then passes through the manual starter so that if the manual starter is engaged power is removed from the electrical starter.

I suppose you could have a spring start in you spares kit. Then if the battery fails OR the starter fails you have an alternate system.

No clue of cost.


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## capta

"If anyone has real world experience with tricks or hacks for kick or hand cranking boat engines to life I'd like to hear about it, and also ideas on how to do that on an engine that no longer has a starting handle crank on hand." 
You could just go buy a crank or have one made by a machine shop!

Sorry, but if you don't release the compression on a diesel, I don't think there is any way to start one without a starter motor. Maybe on a single lunger, but nothing bigger.
Many of the commercial vessels I've run have had hydraulic or air starters. Great idea! One small cargo ship I ran was air start and it could be started off the air tanks or had a hand pump to put enough air in the tank, not quickly mind you, to start the engine. I was told a SCUBA tank would do it as well, but never confirmed this.
Someone could make a nice bit of change building air starters for the most common yacht engines. The nice thing about air and hydraulic starters is that they displace any water that might be in them when used, so they last almost indefinitely.


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## Minnewaska

I was told a story once that said a sister ship started their main diesel by running a halyard down the companionway, around the main pulley and pulled it with an electric winch. 

When I heard it, I was a bit in disbelief, the but fella that told it to me is not prone to fairy tales. I don't think. I also can't really tell where the halyard would have been wrapped. At first blush, I think one would need to remove the belts, which you can't replace, after it's started. There is a big smooth weight, on the main pulley, so perhaps they wrapped that enough to create friction and pull the engine over. I'm still skeptical, but who knows in a pinch.


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## JimsCAL

thvl1 said:


> It has compression release levers so you could do this trick without the dimes or the mess.
> 
> So how come no one puts levers on engines anymore?


My Yanmar 3GM30F has decompression levers. I once had to use them to get it started when I had low batteries. It worked.


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## colemj

The geometry would need to be very lucky for that. Some older engines had a big exposed flywheel which could have been what the halyard wrapped around. Again, lucky geometry.

Mark


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## HUGOSALT

I use my decompression levers on my Yanmar 3 GM here on Long Island sound when sailing
on cold days in November and December. My lead acid batteries last me 6 and sometimes 7 years so they are 
a little tired the last year or two in the cold weather when not so much sunlight for the solar panel.

Years ago was invited aboard an old wooden (barque?) that was anchored between City Is. and Hart Is. in western Long Island sound,
the owner explained that she was only partially completed in Norway when WWII broke out and was completed after the war 
fitted with a surplus U boat diesel which he proudly started for me using compressed air from a scuba tank. Huge diesel caught on immediately.


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## oldfurr

The wrapped a line around the flywheel tale I heard went something along the lines of a Frenchman approaching land at voyages end found himself with flat batteries so he headed off on a reach, wrapped many turns of a spare halyard around the flywheel and ran the tail out through the hatch to a block near the rail outside the cockpit and thence up to the boom, then he gybed. 
Sounds doable to me in a 1/2 baked hideously unsafe way, might also be useful for removing your engine from it's mounts and the shaft without any of that fiddly "removing bolts" sort of stuff if the line failed to pay out as intended, and for removal of unwanted companionway parts in any case.


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## Movingrightalong...

skipmac said:


> One of the things I liked about my old Volvo MD-17C. It has compression release levers so you could do this trick without the dimes or the mess.
> 
> So how come no one puts levers on engines anymore?


Beancounters. The convenience (or lack thereof) to the consumer is secondary to shaving $5 off the construction cost per unit for the builder...and if said design modification turns a 40 year motor into a 20 year motor, so much the better.

People often compare the merits and flaws of sailboat design (well of everything) from the mid 20th century and the early 21st without properly accounting for motives.


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## boatpoker

$100 on Amazon and starts our 55hp Westerbeke seven times. I also use it to power the bilge pump in our dinghy.


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## marcjsmith

Another trick, and would be far easier and less messy than the dimes. Hold something flat over the intake. Basically not allowing the engine to suck in air. No air to compress, faster rotation.

Once spinning fast. Remove the item over the intake.


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## Michael Bailey

This is an old thread but here's my story and solution (almost 40 years ago) We had a very salty Tom Colvin schooner that had a very small single cylinder diesel, just like Tom designed it. No starter on this motor. None. Truth is that I could seldom get it going when it was cold. Even using the decompression lever. My then girlfriend, now wife, usually helped with the lever as I did the cranking. I am afraid that there was a lot of swearing and busted knuckles on my part. We got pretty good at sailing without the help of that engine. The best solution was to invite our good friend Dan sailing. He was a much more powerful man than I. He always could start the d---- thing. We didn't keep the boat long. It was as salty as anything you ever saw. Everybody loved it but it took more man than me to start the motor...


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## capta

Minnewaska said:


> I was told a story once that said a sister ship started their main diesel by running a halyard down the companionway, around the main pulley and pulled it with an electric winch.
> 
> When I heard it, I was a bit in disbelief, the but fella that told it to me is not prone to fairy tales. I don't think. I also can't really tell where the halyard would have been wrapped. At first blush, I think one would need to remove the belts, which you can't replace, after it's started. There is a big smooth weight, on the main pulley, so perhaps they wrapped that enough to create friction and pull the engine over. I'm still skeptical, but who knows in a pinch.


I've got Lewmar 65 ST main winches and I doubt that they would turn an engine over fast enough to start it.


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## JohnGalt

If you have separate house and starting battery banks then they should be able to be paralleled with a switch. If instead you use a knife switch you can either tie them together as 12v or flip the switch the other direction to achieve 24v. Much easier than disconnecting wires to get 24v and once the engine starts you throw the switch back to 12v.


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