jump starting a boat......?

S

Shearwater

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The batteries are full, there is a widget somewhere behind the woodwork making sure both of them are at their fullest. I press the start button and KLUNK! I do not panic, I wait. Again KLUNK! Remembering the advice given after my stroke and heart attack I do not P A N I C!!!.. No. I press again and the engine fires and says "what's the problem?"

So, come the day I really need the one pot Yanmar and it doesn't fire, what can I do? If it was a Morris 8 I'd hit the end of the starter with a hammer, put it into gear and rock it to and fro and bash the battery terminals with the same hammer. My boat has recent had a good looksee by a competent electrician and, just like when you go to the quack with a problem it's over before you get into his/her office, so it is with my starter. Show the boat off and it works 100% every time. Go out on your own and it won't start until the seventh or tenth nail bighting time.

Everything is totally clean and tidy, no leeks or leaks or spills. Can it be the push button starter thingy? The question for the team is this....should I be ready to bypass the push button starter with a stout wire or a pair of pliers or would I get a shock? If all fails and there IS power in the batteries how can I get the starter to kick over the engine?
As ever, thanks in advance to the worthies of amateur boating (and the pros!) from one who knows a lot about other things but not these !!!!!
 
A clunk suggests a bad battery (unlikely as it starts in the end0 or a bad connection.

You can use a screwdriver to short batt. pos. on the solenoid to the small spade terminal to miss out all the key start wiring.

keep that hammer handy!

N
 
Sounds like your starter motor is on its way out to me. Take it off, you can probably get it rebuilt at an auto electrician for £30 and it will be as good as new.
 
Sounds like the classic "hidden Yanmar fuse" problem. I had it on a 2GM20; I don't know whether the 1GM has the same issue but it seems plausible.

Somewhere in the wiring loom where you wouldn't expect it, there is an inline fuse. The connections to this can become loose or corroded, unnoticed because most people don't realise it exists. The symptom is exactly as you describe - one or two clunks and then a healthy-sounding start.

I can't remember exactly where the fuse is; a forum search would probably find it, or wait for a reply here from someone with a better memory than me.

Pete
 
Exactly as Pete describes. There is an in line fuse and it probably needs cleaning. Starter problems with 1GMs are invariably poor connections, so clean them all and check that the ones to the starter button are also clean.
 
learnt to associate tractor starter clunks with terminals not tightened on the battery posts - just pushed on.
so +1 for a flaky connection.
 
There are 2 designs of starter motor and the engagement of the pion into the ring gear. Sorry I don't know which one you have. The first type is where the solenoid (electromagnet) pushes via a lever the pinion into the ring gear along a spline. At the end of this travel the solenoid makes contacts to provide DC to the starter motor itself. In this type the clumk can mean dirty contacts on the contactor. It also can mean rusty spline that the pinion slides on or low battery voltage. (bad wiring or battery)
The alternative design uses a spiral spline such that on giving power to the starter motor the spral spline starts to turn. The inertia of the pinion causes it to slide along the spline and engage with the crownwheel. Often with more noise than the first type. In this type the solenoid (relay) can be remote from the starter. Any rust on the spline means the starter spins without engaging. A very characteristic sound.
In both types a bad battery and often bad connections the starter will try to turn with characteristic rur rur rur as the starterslows on compression then speeds up after compression sometimes starting sometimes not.
Perhaps one of the first things for oP to do is measure the actual volts at the starter. Clip the meter wires on so that he can see the volts when the button is pressed. If the volts p[lunge from 12v down to about 6v or less then it is a battery or wiring problem. Normal is to plunge to about 9v when cranking. If the voltage stays at 12v then the starter is not taking current. This can be a bad contactor or bad brushes in the starter. Both can apear as intermittent problem.
In both cases there is a power circuit from battery through the button or key switch to the solenoid. The solenoid actually takes some significant power so a bad button or key switch can mean not enough power to push the pinion or make the heavy contacts so giving intermittent starts. This circuit can be bypassed with a wire from the battery pos or in some cases in the negative line. Bypassing the key switch may solve the problem. This also is the circuit where a fuse may be hiding with possible bad contacts. It is not uncommon to add a small relay here so that low current goes through key switch to operate a relay whose contacts provide power to the solenoid. I had to do that to my son's Toyota Camry at one stage. Bad key switch.
I hope this helps a little good luck olewill
 
Last edited:
Sneaky Pete said:
Just like your Morris 8 you could bump start it? Put the boat in forward gear and push.........................................very hard.
Click to expand...

I actually bump started my boat once.
I had a fixed bladed prop & was surfing at up to 11 kts in the Dover straits
The prop was spinning as the engine was out of gear
I accidentally kicked the engine throttle lever into gear for a couple of minutes , when I went below I realised that the engine was ticking over
 
On my last boat I had to replace the push to start button due to exactly the same symptoms as described bt the OP. Once replaced I never had a repeat of the fault.
 
I had a similar Problem . Turned out to be knackered starter brushes . cost pennies to replace
 
Jump starting is easy on my boat because the -VE of both starter batteries (twin engines) are both connected to each engine with heavy cables. Therefore jump starting is as easy as a single jump lead from one +ve on one battery to the other. One day I may even put a fixed cable with a isolator switch between the two. Although since purchasing a new battery I probably will never do that.
 
Thanks to all for the advice thus far - please indulge me a little further. The batteries both show 12.87v after a day of no action. With the voltmeter on the solenoid it shows 13.50v. (from whence cometh the extra power?) On cranking, bearing in mind the engine started immediately so it was all very quick, the voltage went to 2.8 then as quickly to 7.5 then to 12.68. I cranked the engine again this time with the decomp lever open and the meter showed 1.20 volts (one point two) for the duration of the cranking - say 4 or 5 seconds. Does this support anyone's theory?

I found the inline fuse and it is perfectly clean and the solder on the connectors is bright. The entire boat has been lightly used only so I have to doubt wear in the starter or the brushes being an issue. All earth connections are good and strong and clean - the second battery and charging thing was installed late 2012. As always, thanks for your tips and hints.
 
prv said:
Sounds like the classic "hidden Yanmar fuse" problem. I had it on a 2GM20; I don't know whether the 1GM has the same issue but it seems plausible.

Somewhere in the wiring loom where you wouldn't expect it, there is an inline fuse. The connections to this can become loose or corroded, unnoticed because most people don't realise it exists. The symptom is exactly as you describe - one or two clunks and then a healthy-sounding start.

I can't remember exactly where the fuse is; a forum search would probably find it, or wait for a reply here from someone with a better memory than me.

Pete
Click to expand...

Different engines, same issue: http://c34.org/bbs/index.php/topic,5078.msg32211.html#msg32211

Most of the time it si NOT the start button or key.
 
Had similar on a vetus generator, never knew when it wouldnt work. Took starter motor apart and the brushes were sticking. Cleaned up with carb cleaner, & has run well for 2 years since.
 
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