I have had increasingly more difficulty getting the bike to turn over when hot. Yesterday, I had to push start it. Then got caught in an accident, got off the interstate and it stalled on the off ramp. Screwed. Buddy came by with tools and cables. Jump started it instantly. Measured voltage on the battery and it was in the 10.5 range.
Now I had been trying to start it for an hour and am sure completely drained the battery.

Okay, I have charged the battery overnight (3 month old AGM).

How can I test to find out where the problem is? What voltages do I look for and where? Under what conditions (rpms)?

Bike has 22,500 on it.

Thanks,

Jon

ok that 10.5 is what... battery with or without drain, or is that while running and at what rpms....

to help you out i need this info...take ur stator wires disconnect them from the r/r and let it run.... take a Meter and mesure the AC voltage comeing from the stator at various rpm... Vulcan versus have what is should be at if you wanna check. then plug it back into the r/r and meausure the battery and see what the voltage is at at various rpm... BTW ur batt is more then likely toast... have it load tested at any auto parts place...

ok that 10.5 is what... battery with or without drain, or is that while running and at what rpms....

to help you out i need this info...take ur stator wires disconnect them from the r/r and let it run.... take a Meter and mesure the AC voltage comeing from the stator at various rpm... Vulcan versus have what is should be at if you wanna check. then plug it back into the r/r and meausure the battery and see what the voltage is at at various rpm... BTW ur batt is more then likely toast... have it load tested at any auto parts place...

Fully charged the battery overnight. Started it up and measured the following (battery term/stator):

off 12.78Vdc
1200 12.22 (Vdc) 21.5 (Vac)
2000 12.55 (Vdc) 29.5 (Vac)
3000 12.78 (Vdc) 40 (Vac)
4000 12.85 (Vdc) 60 (Vac)
5000 12.85 (Vdc) 74 (Vac)

Found an Electrix flowchart said stator should be greater than 50Vac @ 5000RPM, that looks okay. Stator winding resistence should be 0.34 - 0.52 ohms, mine with crap meter (leads alone could be .5 ohms) reads 0.8 ohms. Would verify with a better meter if needed.

Battery voltage is very low, like nothing is going it at all from the charging system but stator output okay?

Ideas?

Jon

It's your regulator. Since you've had the stator disconnected from it, you would have seen if any of the plugs were corroded. Seeing how you didn't say anything about that, then the only other possibility would be a bad ground from the battery to the (wherever the battery ground goes). If that's OK, it's your regulator. Life isn't all that bad for you, after all, is it? Have you done the r/r relocation? Might want to with the new r/r. Anyhow, get one, plug it in, and see how your battery does. Your battery could be toast, as Hizzo said.

It's your regulator. Since you've had the stator disconnected from it, you would have seen if any of the plugs were corroded. Seeing how you didn't say anything about that, then the only other possibility would be a bad ground from the battery to the (wherever the battery ground goes). If that's OK, it's your regulator. Life isn't all that bad for you, after all, is it? Have you done the r/r relocation? Might want to with the new r/r. Anyhow, get one, plug it in, and see how your battery does. Your battery could be toast, as Hizzo said.

Well that's certainly promising news.

Battery took a complete charge, have to see how it behaves in the bike with new regulator. Still under warranty, so if it is toast, shouldn't be a problem.

The stator leads looked fine. The ground is good too.

Yes, I think a relo and new r/r are in order. Hopefully I'll get off that lucky.

Should I even consider a used, ebay r/r? Or just get a new one?

Jon

Regulator new should only cost about $40....Shop the internet

Regulator new should only cost about $40....Shop the internet

Really, haven't seen one yet under $ 90!

Hint?

Jon

Forty bucks? What you been smokin, boy? Ragweed?

Um, I think you should buy a new one. Stick to a name brand. For instance: Kawasaki.

Forty bucks? What you been smokin, boy? Ragweed?

Um, I think you should buy a new one. Stick to a name brand. For instance: Kawasaki.

What about Electrex? BB has them for $90?

Jon

I see them all the time on ebay for 39.95 ($40). They are new.....

Could you supply a link for an example?? I haven't seen any that cheap unless they were off a parts bike, but a link to a valid site that proves otherwise would be nice.

i found mine on ebay for 49 bucks including shipping. when i got it, it was brand new... no dirt no dust, no corrosion from battery leakage... oh and to check the battery, do a load test....cause when u run it dead like u did, it will show a good charge, but the CCA suffer big time cause the metal plates are coated and wont desolve. most auto places do it free of charge.

Could you supply a link for an example?? I haven't seen any that cheap unless they were off a parts bike, but a link to a valid site that proves otherwise would be nice.


oh and i wouldnt suggest electrix.... i dont trust them for some reason... oh yeah its cause when i did my frankenstator mod, and i asked them what would handle my load outputs they replied back that they need a make and model of the bike to see which unit they make for it... when i told them that i had a custom stator, they told me that they were unsure from that point.

i found mine on ebay for 49 bucks including shipping. when i got it, it was brand new... no dirt no dust, no corrosion from battery leakage... oh and to check the battery, do a load test....cause when u run it dead like u did, it will show a good charge, but the CCA suffer big time cause the metal plates are coated and wont desolve. most auto places do it free of charge.

Is that true of an AGM style too?

Jon

Yes, AGM's will do it too.

yes it will. its cause of 2 things. you battery when it discharges, the sulfer will start forming from the battery acid...i.e. you get the sulfer smell on a bad battery. on a good battery when it recharges about 99% of that sulfer will turn back into acid. now when you over discharge the battery, the sulfer drops off the plates, and will no longer turn back into acid when charging. this why batties die.

click mehttp://cgi.ebay.com/ebaymotors/Kawasaki-Vulcan-VN750-VN-750-Volt-Regulator-Rectifier_W0QQcmdZViewItemQQcategoryZ35594QQihZ014 QQitemZ330040326796QQrdZ1

on ebay now

Umm, that's like used. We're talking new for 40 bucks.

mine was 'new' off a 96.... like i said, not a sign of wear and tear...but as always, buyer beware

click mehttp://cgi.ebay.com/ebaymotors/Kawasaki-Vulcan-VN750-VN-750-Volt-Regulator-Rectifier_W0QQcmdZViewItemQQcategoryZ35594QQihZ014 QQitemZ330040326796QQrdZ1

on ebay now

Thanks, was already watching that auction.

Brought it into work today. Going to let a couple of lab guys look at it. After all, we do make power supplies for a living, perhaps, they can come up with a better idea. With as little area as there is for components, I can't see there being too much inside this thing. Perhaps as simple as three diodes and some form of rectifier.

We should be able to do better....we have the technology....

Will advise.

Jon

Go to the electrosport website.....they have a flow chart there on how to diagnose your electrical problem.

That's exactly whats inside one. Three diodes and a rectifier. At least the last one that was shown on this forum.

That's exactly whats inside one. Three diodes and a rectifier. At least the last one that was shown on this forum.

you mean 3 diodes and a regulator? Come on man, cant you get your power components right lol.... :P

yeah that is all that is in there.... you could prolly make one cheaper, and better quality. i just didnt feel like messing with it. just make sure u use parts that can handle 25% extra for safety and use good heat sinking compound and sinks.

you mean 3 diodes and a regulator? Come on man, cant you get your power components right lol.... :P

yeah that is all that is in there.... you could prolly make one cheaper, and better quality. i just didnt feel like messing with it. just make sure u use parts that can handle 25% extra for safety and use good heat sinking compound and sinks.

We took apart the factory unit today. Shocked it lasted as long as it did. Very surprised at the qualtiy of workmanship for a Japanese made part.

Its 6 diodes, three thrysitors, and a control circuit. Put together with no less than three different types of potting compounds. The original intent was to see if a repair was possible, then saw the construction and realized that was out.

The diodes are good, the control circuit is un-documented so couldn't troubleshoot. The control circuit was mostly surface mount components. Most so small I couldn't even see them.

I can see where the thermal issues would be the demise of these. So many different parts to expand and contract at different rates. Thats why they used the different potting compounds to try and equalize the heat tranfer.

Poor solder joints, poor construction techniques (connections pushed together and soldered instead of mechanically secured before soldering), jumper wires crossing over sharp connections, just a mess. Should consider ourselves lucky that these work at all. I am used to our MIL spec work and this made us shudder.

Bought a new one from Rick's out of NH and they claim to make it themselves and claim their design and manufacturing is better than the original. $105 delivered. We'll see.

Jon

Any chance of one building their own???

Any chance of one building their own???

As far as rectifying and regulating, that's not hard. Need to figure out what role the monitoring pin plays.

Jon

the monitoring pin should be a voltage feed back from the ignition switch for the voltage regulator.