Bad Regulator?

[jstluise]

I've been having issues with my battery being drained, leaving me to kick start it sometimes.  The battery isn't very old, so I suspected the electrical system is having issues.  I confirmed that today.

I removed the battery from the system, kick started it, and measured the voltage on the system. 

Warm idle: ~17V (running lights are functioning)
Rev: ~20V
Idle with brake light: ~6.5V

Turn signals don't even work...not enough power to run the relay.  When revving, the turn signals would come on but not flash.

I've been driving it everyday, and everything functions fine (besides the kick starting issue), so I guess my battery has been taking the brunt of the electrical load...not sure.

Scoot has 8200 km on it, and I've heard about the regulators going out around this time.  Are these symptoms of that?  What else could go wrong and is there any other troubleshooting I can do?

Thanks!

[zombie]

Your regulator fried your battery. There should be no more than 14.5 volts above idle speed. One of your diodes is shorted allowing more voltage thru. Replace both the Reg, and the battery. Everything you describe is the way it happens...

[jstluise]

Thanks for the response.  Yeah, I figured it was the regulator.  And yes, my battery is fried...confirmed that when I put it on the charger.  Good sources on a regulator?  eBay?

I'll pick up a new battery and regulator and I should be good to go.

Also, this happened to me on a few mornings:  started up just fine, let it idle 3-4 minutes while I got my gear on, drove out of the garage no problem, but when I went to give it a little more throttle to pull out on the road, I lost power/it stalled for 3-4 seconds.  Then it recovered from the stall and took off just fine.  Happened about 3 mornings about a week ago and that was it.  The way it stalled seemed like the ignition cutting out, rather than fuel.  Wondering if an electrical issue like I am having could screw up the ignition like that...weird though because it wouldn't happen throughout a ride.  The mornings were warm, too...55F.

[zombie]

Ebay is fine for regulators. You will find them as low as 3 bucks. Pay attention to the shipping info tho. Stadium Yamaha is the source for OEM.
Don't sweat the stalling.Try a new plug. Idle is hell on plugs.

[jstluise]

Couple questions:  can overloading the electrical system cause the regulator to fail? and, are the regulators the same between different models?

A few months ago, I was testing out an auxiliary running light to see if my electrical system could handle it.  I got back from a ride and my battery was dead...so it couldn't handle it and I stopped using it.  Could this be a cause of the regulator failing?

I was looking around online and was planning to call a few local places, but I was curious if the regulator is shared between different models of scoots.  If so, which ones?  For example, will a regulator for an Agility 50 work for an Agility 125?  I figured out any 4-pin GY6 regulator will work, specifically for the 152QMI GY6.  $8 on eBay.

[zombie]

Good score on the Reg.
Yes you did fry it with the lamp. The diodes are rated at 35amps@ Theoretically that is 140 amps they can handle but that is PEAK not continuous.
At least it was just the reg/batt.

[jstluise]

Good score on the Reg.
Yes you did fry it with the lamp. The diodes are rated at 35amps@ Theoretically that is 140 amps they can handle but that is PEAK not continuous.
At least it was just the reg/batt.

The running light is a PIAA 35W, combined with the stock 35W headlamp only pulls around 6 amps, plus the 5/20W brake light.  Doesn't come close to 35 amps, which is why I am curious.  I've heard people running 55/60W bulbs without issues...maybe the extra 10-15W for my setup just put it over the charging system's capabilities?  Still doesn't seem like I should have blown the regulator that way (for what it is rated for).

Before all of this happened (before I installed the aux lamp), I noticed my starter not acting a little weak.  It would turn over fine, but if the motor was on the compression stroke, there would be a slight hesitation for the starter to overcome the extra force.  On a fully charged battery (bench charging), the starter had some extra umph!

I never did check the charging system since I bought it last year (PO put in a new battery right when I bought it).  I'm wondering if something else is up with my charging system.  I'll get the new regulator in and check it out.  Hopefully the generator is okay.

[zombie]

Watts, and amps are different. W=VxA. 12volts times 37amps = 444 watts. I do not know your stator but the regulator cannot handle 400 watts. The rectifier section (diodes) can handle 35 amps. (I added up 37 amps continuous). Turn on a blinker, and it is over. There are buffers built in (capacitors) but I really don't know the tru peak rating the regulator can maintain. You can't reason your way out of it. Physics Bro!

Are you a Lawyer by chance?

[jstluise]

Watts, and amps are different. W=VxA. 12volts times 37amps = 444 watts. I do not know your stator but the regulator cannot handle 400 watts. The rectifier section (diodes) can handle 35 amps. (I added up 37 amps continuous). Turn on a blinker, and it is over. There are buffers built in (capacitors) but I really don't know the tru peak rating the regulator can maintain. You can't reason your way out of it. Physics Bro!

Are you a Lawyer by chance?

Not a lawyer, but I am an engineer.  I am not sure what you meant above...maybe you didn't understand my post.

A 35W bulb pulls ~3 amps @ 12V (35W = 12V * 2.9A).  With both my main bulb (35W) on my auxiliary (35W) on, 6 amps is required.  Adding the brake light (20W) and the blinkers (2 * 5W) gives you a total of 100W of power requiring 8.3 amps @ 12 volts. (not sure on the exact wattage of the brake and turn signal bulbs, but I think I'm close).

The stator is rated at 144W @ 5000 rpm, but who knows how good that spec is.

[Shaka]

I'm no expert in electronics, but I know more than most.  I see you used 12V for your math.  Factor in that the regulator regulates the stator output to 14.4V max, that may bust your 144W max....Just saying!

[zombie]

Yeah Shaka! To the rescue. I looked at the 6a as each bulb, and the 20w as amps. + the 5w form the other thing. That's how I came up w/ 22.7 gigawatts. The idea is the system is built for what it has. Adding kazoo's, and whirly gigs are just not engineered into it. You could switch to LED's, and use load resistors for the blinkers. That would allow for another driving lamp. Switch All the bulbs on the scoot. It'll cost about 20 bucks on ebay, and they will last as long as the scoot.

[Shaka]

Yep...switch out all your driving lights and such to LEDs and you will free up some extra power.  As to those that are running 55W headlights...they are just gonna burn out there their electrical system, same as you, or melt their headlight housing...whichever comes first.  These scoots were not designed to run any accessories!  You have to make cuts to be able add additional.

[Vivo]

Sad but true... I've been always thinking on how to improve night visibility for my Super 8. I really need more light. What bulb (35w) can I consider that is brighter or that can give me improved lighting? I'm just afraid to install aftermarket aux light that will just fry my system. Considering the Super 8 having 2 bulbs, It should give more light, stock. Other single headlighted scoots are even brighter.

[jstluise]

I'm no expert in electronics, but I know more than most.  I see you used 12V for your math.  Factor in that the regulator regulates the stator output to 14.4V max, that may bust your 144W max....Just saying!

Yes, I agree with this.  The reason I was using 12V was to get to the original point, which was that the regulator is rated for 35A and with the load on the electrical system you don't even come close to that (even if you use 14.4V).  Just looking for a better explanation on how the regulator can fail when the load is well under what the diodes are rated for...  To me, in this situation, it is the charging system (stator/generator) that is overloaded, not the regulator, and that failure should occur there first before anything happens to the regulator.  Granted, all of this is based on the original claim of a 35A rating for the regulator...I didn't see a spec in the FSM to verify this.

That's how I came up w/ 22.7 gigawatts.

That is way more than is needed to power the flux capacitor...

You could switch to LED's, and use load resistors for the blinkers. That would allow for another driving lamp.

Switching your blinkers to LEDs and using load resistors completely defeats the purpose.

[jstluise]

Sad but true... I've been always thinking on how to improve night visibility for my Super 8. I really need more light. What bulb (35w) can I consider that is brighter or that can give me improved lighting? I'm just afraid to install aftermarket aux light that will just fry my system. Considering the Super 8 having 2 bulbs, It should give more light, stock. Other single headlighted scoots are even brighter.

PIAA has 35W bulbs that produce the equivalent amount of light as a 70W bulb.  This is what I got as my auxiliary lamp, and it is MUCH brighter than my stock 35W bulb.  I am just going to install a relay so my main headlight turns off when my auxiliary lamp is turned on...this will prevent overloading my electrical system.  Either that, or switch all bulbs to LED and get a load-independent blinker relay...that may free up enough to run both headlights at once.  That was my original plan but haven't got around to it yet.