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Hitcher
26th March 2004, 11:29
I know that you can, but SHOULD you jump-start a bike from a car battery?

My poor Zeal hasn't been ridden for a month and its battery is a bit tired...

Motu
26th March 2004, 12:05
If you want to get anal about it - NO WAY!!!! remove the battery and charge it or fit a new one.The spike as you remove the leads can damage those electonic whatchamacallits,but the altenator is not designed to charge a low battery,only maintain the charge it already has,the altenator will be overworked and windings and retifier can be damaged.

Being anal is a pain in the arse - I don't go there...just jump it and go for a fang!

k14
26th March 2004, 12:35
I've done that heaps of times.

Even jump started my mates car off my bike. Didn't blow anything up on my bike. But if yours does blow up, then :Oops:

pete376403
26th March 2004, 12:37
Maybe modern bikes have more delicate electronics but the GS has been jump started from lots of different batteries, both big and small. Getting the leads around the right way is the only thing I've ever worried about.
BTW Suzukis of that era (80's) were notorious for crappy charging systems, so if the regulator was going to be cooked by jump starting it would have happened by now. What ususally happens is the battery dies from sitting to long discharged, as the bike sits in the shed unused (hangs head in shame) but thats no biggie as I have a supply of batteries ex large computer UPS's that work fine.

Jackrat
26th March 2004, 15:06
Well if it's a 1972 Triumph Tiger I would say don't do it,The flames get real high and hot,And running round flapping ya' arms does no good at all.
Belive me, I know!! :o

James Deuce
26th March 2004, 15:08
You can get jumper leads with smoothers built in to protect the CDI/ECU on modern cars and bikes. No more expensive than normal leads either.

Big Dog
26th March 2004, 16:10
You can get jumper leads with smoothers built in to protect the CDI/ECU on modern cars and bikes. No more expensive than normal leads either.
Or you could just read the instructions that come with leads.
One. Turn of the "dead" vehicle, Start the donor vehicle.

Two. Conect the black lead to the earth at both ends.

Three. Connect both ends of the red lead, to the positive post. Donor vehicle first.

Four. Start the "dead" vehicle.

Five. Allow to run for a short while (1min). So you have enough charge to power your spark plugs.

Remove the leads in red first.

Tryt not to touch the red gators to the red gators while any of the leads are still connected.

Following these rules I have started Hundreds of fuel injected motors (working at a car yard) without ever frying a map. This was more common when in older setups where they were silicon chipped instead of pcb chipped.

Keep in mind it takes 30 mins (15 mins in a car) of riding to recover the charge lost starting a bike so you will need to ride for at least an hour unless you are prepared to push start or Jump it again.

Chargers cost less than a chipped set of leads. Mine is a semi automatic one I got for $35 (you just plug it in and wait for the right combination of lights to come on, around 12 hours, it works out the voltage expected itself). From the warehouse (same brand repco sell for $99). If you have a second bike you don't get out much on ask your local distributer about a "tender". You connect it plug it in and it will do everything except check the water. When they need a charge it will trickle charge it so you don't need to remove the caps. Some will even discharge and then recharge the battery (to extend the life) at preset intervals. Expect to start at $59 (I think it I saw them in the motomail mailer for this) and go up according to features.
:msn-wink:

Wonko
26th March 2004, 18:10
Never start the donor car, if the battery can start the car, then there is more than enough power to start a bike. Having the car running will provide minimal extra power. The risk then is that all the electronics will be active, and if anything goes wrong with starting the bike and it surges(for whatever reason), then the chances of damage occuring to the electronics is vastly great if the car is running.

pete376403
26th March 2004, 18:13
Agree with almost all of that except: I connect the reds (assuming negative earth) at both ends first. Reason: if the earth leads are connected and you bump the positive against anything metallic (except the posi battery terminal), there will be sparks. However if you've connected the posi first and bump the earth against anything (except the posi battery terminal, but you're trying to avoid that anyway), well thats all right.
I've seen the effect of big 24v earthmover batteries being shorted - very loud and spectacular. Getting the melted wedding ring out of the guys finger was apparenty difficult and painful.

Big Dog
26th March 2004, 18:23
Never start the donor car, if the battery can start the car, then there is more than enough power to start a bike. Having the car running will provide minimal extra power. The risk then is that all the electronics will be active, and if anything goes wrong with starting the bike and it surges(for whatever reason), then the chances of damage occuring to the electronics is vastly great if the car is running.
I was told that if you are going to do that you need to disco the + lead to protect the donor car from when your alternator cuts in. On the other hand if it is already running anything less than a major surge will be absorbed by the drain to the coil.

Not a big deal if you are starting a 250 with a mack truckbut if you are starting a v8 of your 250 provided you can provide the neccesary CCA (crank amps, the drain the battery is cappable of feeding during start up without the alternators help, most bikes are arount the 100cca, most v8's are around the 440cca) you will get a pulse back as the electricity flows back from the strongest source to the weakest. It would start out going from donor to dead but once it fired it would pulse back the other way. (really lacking intech speak but I'm sure you get my point.)

Big Dog
26th March 2004, 18:30
I connect the reds (assuming negative earth) at both ends first. Reason: if the earth leads are connected and you bump the positive against anything metallic (except the posi battery terminal), there will be sparks. However if you've connected the posi first and bump the earth against anything (except the posi battery terminal, but you're trying to avoid that anyway), well thats all right.

I thought the point was to minimise the damage to electronics?

If that is the case then surely you need a good solid earth before you apply any power.

The quickest way to F*%# a chip is to have the power connected and disco the earth. Won't say how I know I just do okay? $300 mutter mutter mutter.

DEATH_INC.
27th March 2004, 08:25
I can tell you that a gixx750 will not recharge a dead battery after jumpstarting and will get the rectifier so f*****g hot it will burn your hand if you touch it.....

speedpro
29th March 2004, 21:26
I thought the point was to minimise the damage to electronics?

If that is the case then surely you need a good solid earth before you apply any power.

The quickest way to F*%# a chip is to have the power connected and disco the earth. Won't say how I know I just do okay? $300 mutter mutter mutter.
It's a circuit and therefore doesn't matter whether you break the circuit on the red wire side or the black wire side. Either way the electricity stops flowing round the circuit.

For safety from big sparks I always put the black/negative lead on last and off first.

scumdog
7th April 2004, 20:50
Got it wrong on my old Iron-head sporty once, used two sets of jumper leads end-to-end (couln't get the car close enough).
Fierst it fried the regulator and the ignition light would not go out but hey, it started! Then I just couldn't wait to run in the new engine by heading to the Hokonui rally, figured the new battery I had just bought (so I did not need to use the jumperleads) would keep the engine alive as long as I did not use the headlights.

Got back from the rally o.k., put in a new regulator ($200) but still the light stayed on, off to the autosparky and lo-and-behold I had overworked the generator and burned out the armature ($200 again), add the cost of the generator rebuild and that 1/10th of a second stuff up worked out at an hourly rate of about $1,235,00!!!!! - still, as they say, good entertainment don't come cheap!

Seriously, hook up hot wire, then earths and make sure neither vehicle is switched on at the time THEN start the flat-battery vehicle as normal WITHOUT running/turning on the 'donor" vehicle

Motu
7th April 2004, 21:56
Same here,I'm on my 4th stator,3 burnt out by a faulty reg,it was showing a charge but dumping too much and overloading the alt - alt case temp 120c,I was told these things always run hot.

FROSTY
11th April 2004, 00:41
To save yourself the problem in the future you can buy trickle chargers.
They just maintain the battery in its fully charged state.
I saw them advertised in Motomail and thought it was a good idea . :done: