ok so  look at it this way, it most likely isn't going to hurt anything leaving the car running to boost the bike off, but a car battery has more than enough "juice" to start the bike, so why run the motor if there is even the slightest chance it may damage it?

I wasn't going to get into this, but I agree with Jeremy.  Seems like you'd just be waisting gas by running the car, and right now, I need to save as much as possible.  So, next time my bike needs a jump, I'm gonna use the car battery to jump, but I'm not gonna start the car first, not because I am afraid of ruining the bike, but because I don't want to run the car.

I also don't take bags that I am offered (from stores) for things that I can hold in my hand(s), and I don't live in a house with rooms that I don't use every single day.  I'm funny like that, I try not to waste.  Sorry... rant over now.

-SPiNNeR-

Quote from: ojstinson on June 26, 2010, 05:48:41 PM
Me? sarcastic?, perish the thought.

Think about it, do you really think anyone is going to jump start their bike with their car engine running after this---I stand by my statement about not using a running car to start your bike.


I think you and Sledge had better arm wrestle over the increased voltage- more current issue;

         You.
"IF the donor vehicle's system is providing too many volts, then more current will flow through the starter, causing excess heat and possible failure".

       Sledge.
"You will find it states that in a DC circuit if power remains constant and voltage increases, current DECREASES, not as you claim increases".



I'm so confused!

OK, sledge has made an assumption that power is a constant, but I would disagree with that. In fact, the nearest thing to a constant is the resistance, which is just a physical characteristic of the thing being measured. It can vary a bit with temperature, but within a moderate voltage range it will not change much. Given that, then I stand by my analysis, and that's why I would agree that running the donor engine is more likely to overload the starter if you abuse it by overuse. However, as I said before, it will not affect any other components of the electrical system as the voltage when jumping is no more than when your bike is running normally.

Quote from: ojstinson on June 26, 2010, 05:48:41 PM
Think about it, do you really think anyone is going to jump start their bike with their car engine running after this---I stand by my statement about not using a running car to start your bike.

People hear what they want to hear. 

I've jumped a single-battery truck with 6-battery... let's say.. "heavier equipment", more times than I can remember.  With the donor turbine engine running at quite high rpm. 
(I'll let you wonder about the parallel vs series)
No blown starters, batteries, relays, or melted fuse boxes. 
If anything, it takes some of the scale off the anodes, like a deep-charge cycle. 

Mathematically?
Ohm's Law be d@mned.  The slightly increased amperage does next-to-nothing, it's why you're not using extremely tight tolerance fuses (which would blow if at high rpm, anyway).  The R/R does it's job, the wiring is stranded higher than it needs to be, and the battery can take it. 
A more important equation is the work being done by the starter motor, given higher current with constant coil winding.  The heat from 3 extra volts (GM alternator at max output) is irrelevant, especially on a starter bolted to an air-cooled engine. 

It's your exhaust bearings that you should worry about.   

Funny, I've been reading about not starting your bike from a running car on this forum for years and nary a peep, I say it once and electrical engineers start pouring out of the woodwork---I'm just glad I could be of assistance in finally putting to rest this old myth.

Here is a testimonial from Mary who has finally gotten closure on this issue.

"I love the explanation sledge! So many people are worried about a car electrical system "forcing" it's high current on the bike and frying everything. I've read it in all of these posts about electrical problems. Thanks for the DC Circuit lesson for those who haven't had one"!


And Homer;

"It's your exhaust bearings that you should worry about".

To be more specific it's the mufflers that have the bearings ( fore and aft ), straight pipes don't require them. And for you nautical people remember to always use "Relative Bearing" grease.

You're of assistance like a kid trying to barbecue. 
Takes too much time to explain, and the payoff isn't worth it.  Just keep the heat really low so you don't burn the bratwurst, and you'll still feel like a hero. 

















And, exhaust bearings are in the valvetrain, not the muffler. 
n00b.   

Nice try Homey, what a blistering comeback,  takes my breath away.

And by the way, while you're out pick up a sense of humour.

You're the one that can't figure out Ohm's Law, master of the dry wit. 

I just use a portable jump pack....  

I'm with Sledge on this one.  But those of you that disagree next time you take your Play Station to your friends houses be careful in case they have a higher amperage transformer on there block you might force to much current into it and it will turn into a transformer (The kind that turn into cars. They are real you know) kill your wife and rape your dog.   I would be more worried about the GS spiking the ECU in your car and killing that. But with modern jumper leads that is highly unlikely also now they are almost all fitted with surge suppressors.. And if they're not you can overcome this by putting the negative side of the leads on the block or chassis.

Good luck fixing your bike Zilla

If you do not have the car running the gs will try to charge the car battery as soon as the engine starts.  This might get tough on your charging system  since it will require more current the usual to charge your dead gs battery, plus u much larger battery.  You should leave the car running.  It won't take very long anyway so it won't be much gas.

Got it running with a new starter solenoid from eBay ($30).

The electrical starting system has a 20A fuse which protects the bike.so I wasn't worried about harming it with the car running. I agree with kman's point on charging the car's battery once the bike starts if the car wasn't running. Higher potential energy, or voltage, always wins. Thanks!