SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> Weak spark
/cgi-bin/YaBB.pl?num=1194189929

Message started by cFLOW on 11/04/07 at 07:25:29

Title: Weak spark
Post by cFLOW on 11/04/07 at 07:25:29

I have a delimea my motor wont turn start it turns overs, but wont start. pulled the plug and it has a weak spark that seems to weaken after each crank. I'm thinking its the battery but I cant test myself, multi meter dead. The starter also seems to slowing after a few cranks I charged the battery over night but its still doing the same thing. does this sound like the battery to anyone else or something else. Thanks

Title: Re: Weak spark
Post by Savage_Greg on 11/04/07 at 07:30:53

Boy everything is having problems. First, I'd put some new batteries in that meter so you can check the bike's battery.

The battery sounds to be about shot if you charged it and the starter turns slow with the plug out of it.

Actually, I think that you know where to start, just by reading this :P

Title: Re: Weak spark
Post by verslagen1 on 11/04/07 at 09:02:01

With a bad battery, you'll be able to turn over but there won't be any juice left for sparking.

You can try push starting.

Title: Re: Weak spark
Post by cFLOW on 11/04/07 at 11:33:29

Its the battery, 11 volts so its dead.

Title: Re: Weak spark
Post by barry68v10 on 11/04/07 at 11:36:10

That may have been the easiest thread yet ;D

Title: Re: Weak spark
Post by islandwahine on 11/04/07 at 16:16:09

cFLOW wrote:

Its the battery, 11 volts so its dead.

isn't the battery only 12 volts?
So that one volt make a difference?

Title: Re: Weak spark
Post by verslagen1 on 11/04/07 at 16:22:26

well when you turn it over the batter is going to drop more.

11 volts says at least 1 cell is dead, maybe 2.

Title: Re: Weak spark
Post by barry68v10 on 11/04/07 at 17:24:10

A battery cell has a voltage of around 0.9-1.2 volts nominally. Lead-acid batteries tend to have a little less voltage per cell than some others like Nickel-Metal Hydride or Nickel Cadmium...etc.

Title: Re: Weak spark
Post by verslagen1 on 11/04/07 at 17:54:41

FYI: from Wikipedia

The following are general voltage ranges for six-cell lead-acid batteries:

Open-circuit (quiescent) at full charge: 12.6 - 12.8 V
Open-circuit at full discharge: 11.8 - 12.0 V
Loaded at full discharge: 10.5 V.
Continuous-preservation (float) charging: 13.8V for gelled electrolyte; 13.5V for AGM (Absorbed Glass Mat) and 13.4V for flooded
All voltages are at 20C, and must be adjusted for temperature changes.
Float voltage recommendations vary, according to the manufacturers' recommendation.
Precise (+/- 0.05V) float voltage is critical to longevity; too low (sulfation) is almost as bad as too high (corrosion & electrolyte loss)
Typical (daily) charging: 14.2 - 14.5 V (depending on manufacturer's recommendation)
Equalization charging (for flooded lead acids): 15 - 16 V
Gassing threshold: 14.4 V
After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.

Title: Re: Weak spark
Post by Max_Morley on 11/04/07 at 18:06:54

Some real life numbers from the old auto shop teacher. Open circuit battery voltage with a DVOM (Digital Volt Ohm Meter not analog {meter type} loads the battery slightly so won't work here) should be 12.6 volts. Each cel produces 2.1 volts x 6 = 12.6. if it has just come off a charger or running engine it could be slightly higher. During cranking it should not drop below 9.6 volts at 70 Deg F, in reality it should stay well above 10.5 V if the battery is in good shape and the starter current draw isn't excessive or the engine has mechanical problems. Colder battery temperature may drop down to 7.5 V or so and still be OK. It may not start the engine however as the electronics do not want to not work at about 10 V or less. Broken wires in the cables from the battery, corrosion in the connections, loose connections, and undersize wires all can mean the engine will not crank like it should. If it doesn't crank like it should, it probably won't start. Max

Title: Re: Weak spark
Post by T-Mack1 on 11/04/07 at 19:45:22

To add to the thread...

You could have a "good" battery that is just not fully charged at 10v and still start the bike.

You could have a bad battery at 13.6v and it won't....

Remember batteries are chemical reactions. On common car & bike batteries, Lead plates sitting in acid. the chemical reaction creates some volts. Like Max says, colder less voltage, because cold slows down the reaction.

Common ways batteries wear out:

- Shorting of the plates which is caused by the Byproduct of the chemical reaction. Crud builds up on the bottom from the acid eating away the lead.

- Corrosion, the lead can get covered by corrosion/oxidation if they get discharged too many times. This causes the battery to deliver less current, but it can have same voltage. Remember Power (wattage) runs things and power = voltage x current. If you have voltage but little current, it won't go.

Title: Re: Weak spark
Post by Savage_Greg on 11/06/07 at 05:09:44

There's a big word used for the corrosion in a lead acid battery... is it?

Sulfication or sulfaction?

It's still early :P

Title: Re: Weak spark
Post by T-Mack1 on 11/06/07 at 09:44:30

Savage_Greg wrote:

There's a big word used for the corrosion in a lead acid battery... is it?

Sulfication or sulfaction?

It's still early :P

Yea, I went round and round wondering if corrosion was the right word to use. Added Oxidation only because I couldn't remember what was in the acid. But we add water to the battery and it's got O2 in it. But.....just looked in a dictionary and corrorsion is " wear away by chemical action" ... hmmmmmmmm......

Title: Re: Weak spark
Post by verslagen1 on 11/06/07 at 10:01:18

Savage_Greg wrote:

There's a big word used for the corrosion in a lead acid battery... is it?

Sulfication or sulfaction?

It's still early :P

Sulfication is bandied about by the battery charger folks.

Title: Re: Weak spark
Post by barry68v10 on 11/06/07 at 13:30:25

From VT engineering dept. "The electrical force produced by an electrochemical cell is measured by the cell voltage. Cell voltage depends on the redox reactions occuring in the cell and the concentration of the reactants, but not on the number of electrons passing through the cell: it is an intensive property. The standard voltage E0 of a cell is measured when all reactants are at 25oC and at 1M concentration or 1 atm pressure.

For a copper-zinc cell like

Zn|Zn+2||Cu+2|Cu
the standard cell voltage E0 = 1.101 V.
Since we can split a redox reaction into two parts, we can also define standard voltages for both the oxidation and reduction parts of the reaction, Eox0 and Ered0. We arbitrarily pick the hydrogen reduction half reaction

2H+(aq) + 2e- -> H2(g)
to have Ered0 = 0, and measure all other half reaction voltages in relationship to it.
The oxidation half reactions are just the reaction run in reverse, and the half cell oxidation voltage is just the negative of the reduction voltage. For example:

Reduction: Zn+2(aq) + 2e- -> Zn(s) Ered0 = -0.762 V
Oxidation: Zn(s) -> Zn+2(aq) + 2e- Eox0 = 0.762 V
The standard voltage of a cell, E0, is just the sum of the standard voltages of the oxidation and reduction half reactions. This is independent of the number of electrons in the half reaction: if you need to multiply a half reaction by 3 to balance the redox equation, you do not multiply the cell voltage by 3. For example, the zinc-copper cell above is made up of the reactions

Oxidation: Zn(s) -> Zn+2(aq) + 2e- Eox0 = 0.762 V
Reduction: Cu+2(aq) + 2e- -> Cu(s) Ered0 = 0.339 V
E0 for the cell is Ered0 + Eox0 = 0.339 + 0.762 = 1.101 V
Example: What is the standard voltage for the cell

Mn|Mn+2||Fe+3|Fe+2
Solution: First, seperate the cell into two half reactions

Oxidation: Mn(s) -> Mn+2(aq) + 2e-
Reduction: Fe+3(aq) + e- -> Fe+2(aq)
The iron reduction has a voltage of 0.769 V. The oxidation of manganese is not listed, but the reduction (reverse reaction) is listed with a reduction voltage of -1.182 V. The oxidation thus has a voltage of +1.182 V
To compute the cell voltage, simply add the two voltages. It doesn't matter that the manganese reaction has two electrons and the iron only one

E0 = Ered0 + Eox0 = 0.769 + 1.182 = 1.951 V"

So, my 0.9-1.2 volt number was the oxidation portion of the reaction, didn't account for the reduction portion...

Title: Re: Weak spark
Post by verslagen1 on 11/06/07 at 13:36:39

Becareful what you ask a phd. ;D

Title: Re: Weak spark
Post by barry68v10 on 11/06/07 at 13:56:11

verslagen1 wrote:

Becareful what you ask a phd. ;D

My dad keeps telling me this stands for "piled higher and deeper" ;D

Title: Re: Weak spark
Post by Reelthing on 11/06/07 at 13:56:13

A single actual test on the garage floor says the '02 Savage will crank at 12.26v but will not start -
at ~12.30v the ign module finally fires properly and it will start - the rule of thumb for an agm battery states:

open circuit voltage.........state of charge
........12.80 or greater............100%
...............12.60.....................75%
...............12.30.....................50%
...............12.00.....................25%
...............11.80......................0%

The actual stabilized OCV can only be determined after
the battery has been disconnected from a charge source for 24 hours - this allows the float to dissipate

Title: Re: Weak spark
Post by Savage_Greg on 11/07/07 at 09:42:42

"Piled Higher and Deeper". Now that's something that I can understand :P

Let me see if I can summarize this for all the newbies...

If your battery is floating but doesn't have enough stable voltage and/or your battery has a bunch of oxidized white stuff worn off in the cells, then it is highly possible that you can experience a wimpy spark!

Did that help? ;D

Title: Re: Weak spark
Post by verslagen1 on 11/07/07 at 10:06:58

"Piled Higher and Deeper" - That's what all my prof's called it to. And I think they also refered the university as the mushroom factory.

If your battery is floating... add electrolite and charge.

If you can see a bunch of oxidized white stuff worn off in the cells... You must have a glass case and your battery is older than the hills, time to replace. ;D

Title: Re: Weak spark
Post by Savage_Greg on 11/07/07 at 10:28:38

verslagen1 wrote:

So that's it!

Engineer = Blooming Mushroom ;D

Title: Re: Weak spark
Post by verslagen1 on 11/07/07 at 11:10:35

Naw, we engineers are still mired in muck, just spores or worms.

The bloomin' mushrooms with their heads in the clouds, were PHD's of the physics kind.

Title: Re: Weak spark
Post by Savage_Greg on 11/07/07 at 12:30:46

verslagen1 wrote:

Naw, we engineers are still mired in muck, just spores or worms.

The bloomin' mushrooms with their heads in the clouds, were PHD's of the physics kind.

Well, I know all too well, that when engineers are mired in muck, the technicians are buried in.............:P

BTW - did we help cFlow out or did he just give up on us? It's been fun anyway :)

Title: Re: Weak spark
Post by cFLOW on 11/07/07 at 17:44:03

It turned out that the ignitor also had a bad ground too. so I have new battery (free under warranty) and I just have to finish the tank now. thanks for all the added info Im sure this will help someone else also.

Title: Re: Weak spark
Post by Digger on 07/08/08 at 20:19:27

4F787871697574737A1D0 wrote:

The actual stabilized OCV can only be determined after
the battery has been disconnected from a charge source for 24 hours - this allows the float to dissipate

A quick way to get rid of the "float" or "surface" charge is to turn on the ignition and select the high beam. Don't start the bike. Let the headlight burn for three minutes, turn the ignition off and wait five minutes. You should now be able to get a good OCV from the battery.