engine hangs when first trying to start

Sven

Well-Known Member
Can't be:
1. The EHC.
2. The wiring.
3. The stator if it eats batteries.

Can be:
Voltage regulator... where...
... Stator output has full load to battery and the regulator is not stepping down the voltage out of the stator.
 

Mikeinjersey

Well-Known Member
It's possible the new battery was defective. If not, it's not easy to fry a battery without some evidence like smoke or melted wires. Look for blown fuses or popped circuit breakers. Sven is on to the likely problem. When you install the new battery disconnect the VR from the battery circuit before you start the bike. The bike doesn't need the charging system to start or run. If all seems well at that point come back for info on checking your VR and Stator before connecting it to the battery again.
While jumping your bike you may have inadvertently smoked something. Good policy for if you use a car to jump your bike is to keep the car off and not charging.
 

Coolbreezin

Active Member
Hey Mike. Thank you for all your advice and time. No smoke or any indication of being defective.
1) the new battery started the bike for a few days. Went out riding and everything.
2) because I removed the brain, there's only one fuse, the 40amp. No breakers.
3) I'm just not understanding how the VR has anything to do with starting the bike.
4) car was off.
 

Mikeinjersey

Well-Known Member
The VR charges the battery. When you use the bike, starting it takes a lot of power along with the headlight and other lights and accessories. If the battery doesn't recharge eventually the battery dose not have enough punch to start anymore. If it worked for a few days before giving you trouble again it seems it's likely the charging system is not functioning properly. The 40 amp fuse is probably between the battery and the VR to prevent meltdowns or fires. Check the fuse to be sure and then put the new battery in with the VR disconnected just to be safe.
You say the new battery is fried. Have the shop you bought it from test it to see if it's shorted internally. No chance you hooked the battery up backwards when you jumped it? If so that could do it. Just don't tell the shop you jumped the battery or they may not honor the guarantee.
Let us know how you make out.
 

Jersey Big Mike

100K mile club
Hey Mike. Thank you for all your advice and time. No smoke or any indication of being defective.
1) the new battery started the bike for a few days. Went out riding and everything.
2) because I removed the brain, there's only one fuse, the 40amp. No breakers.
3) I'm just not understanding how the VR has anything to do with starting the bike.
4) car was off.
If during the days that you rode the bike the VR was bad and either allowed to much voltage ie above 14.4v DC it could have easily fried the battery. Depending on mileage you did would determine how fast the battery died.
This is more likely than the starter taking out the battery without signs of melting severely overheating wires.
Have that Lithium tested if you can.

When you get a new battery disconnect the VR until after you solve cranking issue and test the stator/vr
 

Sven

Well-Known Member
3. The VR has nothing to do with starting. The VR stabilizes the battery from cooking the acid out of it.
Technically this is not how it works, but to play with the numbers you can see what the VR does.
Stator makes AC so you see the two wires out of the stator. Say it's a 32a stator. North has 16v and South pushes 16v up the other side of that wire.
The VR takes and chops 1.6v off each 16v and 14.4v enters the battery. No VR to chop that partial volt, all 16v goes into a battery and the heat is the boil, the heat is the buckle, the heat is the bulged battery case. The smell would be noticeable being near the bike.

4. Car battery is like a meat locker as opposed to the freezer size in the fridge. Same 12v, just stores a lot more, so balance wise, you are pulling the same amps and can't hurt the EHC seeing 12v.

So a bad battery or the VR is eating batteries. You go right back to having the volt meter across the battery posts, watch the draw on start, then you read it like this:
A. Starts-loads-returns back to 12.7v and remains there while the engine is running = No stator output.
B. Starts-loads-returns back to 12.7 and is showing over 14.2v at idle = No Problem and all 3 are functioning as should.
C. Starts-loads-returns back to 16v+ and do not rev the engine, but kill it = VR is not regulating that 1.?v, but straight into the battery and cooks it dry.
 

Jersey Big Mike

100K mile club
3. The VR has nothing to do with starting. The VR stabilizes the battery from cooking the acid out of it.
Technically this is not how it works, but to play with the numbers you can see what the VR does.
Stator makes AC so you see the two wires out of the stator. Say it's a 32a stator. North has 16v and South pushes 16v up the other side of that wire.
Ok, I'll admit you are saying this isn't correct but it's SO far off I have to say something.

32A stator does not mean 32V AC

The VR takes and chops 1.6v off each 16v and 14.4v enters the battery.
Taking 1.6v off the "north" results in 14.4, taking 1.6v off the "South" results in -14.4v - That's a total of 28.8 volts if applied to the battery. If you had mentioned that it inverted the south then clipped the 1.6v that would have been a bit more correct.

The VR rectifys the AC to DC then it "clips" the voltage.

Simplifying the concept is great Sven, but some of your posts go too far and off the rails in your attempt to dumb down things.
 

Sven

Well-Known Member
That's a total of 28.8 volts if applied to the battery. If you had mentioned that it inverted the south then clipped the 1.6v that would have been a bit more correct.
Let me interject. That's a single sweep of 16 up the wire and now clip the North. That's already entered into the battery. The South is going to come in and that too is clipped and sent to the battery. It's a constant 16-clip = 14v to the battery at each half sweep, not 28v at once. N and S make sense now in the dd? That's how I see it.

The VR rectifys the AC to DC then it "clips" the voltage.
I read the way the VR clips. I just don't recall the tech side of it. But as you know, I like to take anything and apply the science to it in the shortcut way of the complex.

Simplifying the concept is great Sven, but some of your posts go too far and off the rails in your attempt to dumb down things.
Gotta love the dd so I can figure it out. :oldread:
 

Sven

Well-Known Member
For example, If I said each core has a N sweep and as it moves to the next core, it reverses. So each core is posi then neg in the AC of it. But if you act the one way diode and capture each pulse and not think back and forth... you fidget the number 32, split N and S equally to 1/2. You already see a charging system is showing 14v and then you get this :boing: going, and come up withishit... aka, SvenSpeakShit outhe ass enderstanding it a little clearer... cough, is the attempt.
 

Jersey Big Mike

100K mile club
For example, If I said each core has a N sweep and as it moves to the next core, it reverses. So each core is posi then neg in the AC of it. But if you act the one way diode and capture each pulse and not think back and forth... you fidget the number 32, split N and S equally to 1/2. You already see a charging system is showing 14v and then you get this :boing: going, and come up withishit... aka, SvenSpeakShit outhe ass enderstanding it a little clearer... cough, is the attempt.
Again part of the point really was more just because its 32A does not mean 32V
Point in fact most 32A stators at 3K rpm or above are probably closer to 50-60 volts.

The VR
First it turns AC into DC
The it regulates the DC which when just rectified is "noisy" and above the 14.4v you need for charging.
The regulator then smooths and sets the output voltage.

Let's end this hear and not hijack this thread any further please.
 

Coolbreezin

Active Member
OK, put an AGM to test the :moped:. Plugs are out, engine spins great. I put one spark plug back in and the engine struggles a little then rotates to the next stroke and struggles till the battery smokes a little. I switched the holes and the same thing happened. But both CR's go down when I turn the key. I was told to disconnect the VR before trying to start. I forgot to do that this time but will. So I just cant figure this out.
Since its narrowed down to a compression and/or CR issue, any advice?
 

Mikeinjersey

Well-Known Member
OK, put an AGM to test the :moped:. Plugs are out, engine spins great. I put one spark plug back in and the engine struggles a little then rotates to the next stroke and struggles till the battery smokes a little. I switched the holes and the same thing happened. But both CR's go down when I turn the key. I was told to disconnect the VR before trying to start. I forgot to do that this time but will. So I just cant figure this out.
Since its narrowed down to a compression and/or CR issue, any advice?
Post 24 Voltage drops to 5.5 vdc when you hit start.
Post 30 New battery all good
Post 36 7 days later back to square one
Post 41 battery voltage drops to 5 vdc
Post 42 Another try turned key ,loud click Fried battery
Post 53 New or different battery cranks with struggle but also smokes.

Seems to be a large circle with symptoms of a short making the battery smoke. If the CR's are activating immediately when you turn the key on that would indicate a short. I'm thinking your just leaving out the fact your hitting the start button.
New strategy: Look around for melted wires which may help isolate the issue. Make sure your battery is tested and fully charged to at least 12.8 vdc sitting. Disconnect the VR from the battery. Remove the green wire from the starter solenoid and read the voltage when you hit the start button. Should be approx 12vdc and also you should hear the CR's click. try it several times unless you see the large voltage drop again.
If it still drops to 5 or so Volts you will at least know the short is not your starter sucking the life out of the battery and that the short is elsewhere on the bike. You will need to isolate the circuits. Shorted headlamp connector is possible and a good place to start but I think you said that was ok. Let's see how you make out and come back if you have any specific questions.
Leave the starter disconnected until you find the problem it will only drain you battery even more. Also leave the VR disconnected while isolating the short, it can be tested later.
 

Coolbreezin

Active Member
Seems to be a large circle with symptoms of a short making the battery smoke. If the CR's are activating immediately when you turn the key on that would indicate a short. I'm thinking your just leaving out the fact your hitting the start button.
New strategy: Look around for melted wires which may help isolate the issue. Make sure your battery is tested and fully charged to at least 12.8 vdc sitting. Disconnect the VR from the battery. Remove the green wire from the starter solenoid and read the voltage when you hit the start button. Should be approx 12vdc and also you should hear the CR's click. try it several times unless you see the large voltage drop again.
If it still drops to 5 or so Volts you will at least know the short is not your starter sucking the life out of the battery and that the short is elsewhere on the bike. You will need to isolate the circuits. Shorted headlamp connector is possible and a good place to start but I think you said that was ok. Let's see how you make out and come back if you have any specific questions.
Leave the starter disconnected until you find the problem it will only drain you battery even more. Also leave the VR disconnected while isolating the short, it can be tested later.
[/QUOTE]

Awesome info. Thanks Mike. About 3 years ago I had the whole bike rewired to remove the brain. With that I also had a marine grade ignition to replace the Run & Start buttons (the pods died about 6 years ago). So it starts like a car, and I have a slam button. The battery I used today is a new AGM 310cca I trickle charged until full. This battery spins the engine fine with no plugs in, but slowly went to 5.5volts only after struggling with one spark plug in.
What about r&r electric CR's to manuals in same hole? Been wanting to do this for a long time.
 

Jersey Big Mike

100K mile club
OK
Disconnect the VR
Pull both plugs
Spin engine over <3secs
If it spins freely still, attach volt meter to ground and loose vr output and see what you read there. Use a cheap meter just in case. (harbor freight $5 special)

You likely culprits are a SHORT (I'm not leaning in this direction since with no plugs it spins well)
VR bad and killing batteries and potentially damaged starter as well.

NEVER hold the start long enough to smoke wires always less than 3-5 secs max.

If you got smoke more than once you may have damaged new battery.
 

Sven

Well-Known Member
Sounds like way too much compression and you need to sell that bike... PM me for offer to sell.

Let's try this:
1. Charge battery for at least 24hr on trickle. Go out and buy the matching charger. In other words, say the battery is 12N12a. It takes a decimal to the right to see the minimum charger needed and that says 1.2a battery charger read on the back of the charger somewhere. Where now you have this 14a size battery and if you charge the batt with a 1.2a, then where is the extra .2a
that says; charge a 12N14a battery for 14hrs @ 1.4a rated charger.

So balance is going to be a 1.2a rated battery in a 1.4a batt? You'll need at least a 1.5a charger rated at the back of the charger.

2. Now that the battery is fully charged for all those hours and its rating at said charge hours, now install it in the bike for service.

3. Both plugs out, read the volt drop at the battery. Install one plug. What is the volt drop now? And with that said that it keeps dropping, then it has to be the compression units not opening.
 

Rottweiler

Well-Known Member
About 3 years ago I had the whole bike rewired to remove the brain. With that I also had a marine grade ignition to replace the Run & Start buttons
Question #1
What are the CR's wired to now?
#2
When you get 5 volts at battery is that only while the starter is trying to turn over the motor? Then back to 12 later?

Thanks
 

Coolbreezin

Active Member
Question #1
What are the CR's wired to now?
Wired to starter with oem green wire.
#2
When you get 5 volts at battery is that only while the starter is trying to turn over the motor? Then back to 12 later?
Yes.
 

Mikeinjersey

Well-Known Member
Not sure about manual CR call S&S . I know they have 14mm plugs but not sure about Manual cr's that fit.
OK you must have some sort of terminal block that all your wires are connected to like a Motogadget M-Unit. Leave your VR and Starter disconnected (that way you know they are not the involved) and start removing one circuit at a time and watch for less change in voltage drop. Example : if you remove a circuit and the voltage drop when you turn the key is a volt or two instead of 7 it would indicate that circuit has the short because all is good with it disconnected. If the drop stays @ 7 it would indicate that circuit is not involved in causing the heavy voltage drop. Continue until you isolate the problem.
 

Rottweiler

Well-Known Member
Disconnect both CR's from the green wire at the starter.. Check each wire to ground with a ohm meter. Leave both plugs out. See if the starter spins fine. You might have a bad CR?
 

Rottweiler

Well-Known Member
The way it is wired, it sounds like the CR should be open the whole time the starter is spinning? When it worked before this problem, did it fire up while the start button was pressed or right after it was left off?
 
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