Kawasaki VN750 Forum banner

1 - 19 of 19 Posts

·
Registered Badass
Joined
·
102 Posts
Discussion Starter #1
I'm having all kinds of electrical problems.
Started with the voltage being too low while the bike is running. Idle seems normal but even at 5000RPM I'm getting around 12.5V.

The RR was replaced a couple years ago so I'm not sure if that's faulty already.

One thing I did that might be a clue to someone. With the bike running I pulled the fuse to the headlight. The battery did read about a volt higher at all ranges. Which probably just means the light draws a volt. The odd thing is that when I put the fuse back in (bike still running) the light did not come back on. If fact, that light hasn't lit up again ever since.

I tested the junction box and some of the pins have resistance instead of infinity. And pin 15 only seems to work when I wiggle it. So obviously the junction box is in need of replacement.

Now to the stator, which worries me. I checked all three yellow wires and they all have continuity with ground. All combinations only give about 10V AC. I'm not sure if the low voltage is because the stator is dead or if it's because most of the current is grounding out.
I inspected the wires under the left engine plate and saw nothing that seemed unusual. I replaced them anyway but as you might expect there was no change.

Is the stator for sure screwed? Could a bad stator have damaged the junction box? Or could a bad junction box damage the stator?

Any insight would be appreciated. I've searched the forums as best I could but none of the previous threads that I saw mentioned how to deal with grounded out stator wiring or if this could even be normal.
 

·
1986 VN750
Joined
·
3,255 Posts
From everything I've read those reading indicate a bad stator. The stator goes directly to the R/R so I doubt the junction box caused the stator to fail. A bad/failing R/R can cause a stator to go bad eventually, however. You should test the R/R since it's quite easy if you have a multimeter with the appropriate capabilities.

Set the multimeter to the diode test. Place your negative multimeter lead on the positive connection on the R/R (top left). You should get a beep (good) on all 3 stator (bottom 3) connectors on the R/R. Now test with the positive multimeter lead on the ground connector on the R/R (top right) to all 3 stator connectors (bottom 3). You should get a beep on all of those as well. A solid tone or infinite reading on most multimeter means a bad diode.

I believe testing positive to negative on the R/R with either lead should generate a good beep as well.

Hope this helps.
 

·
Registered Badass
Joined
·
102 Posts
Discussion Starter #3
Thanks for the info. I've never used the diode test on my meter before so maybe I did something wrong but I got absolutely nothing when checking those pins. I tried the continuity test as well and also got nothing with that. Perhaps my RR is fried too.
 

·
Premium Member
Joined
·
5,236 Posts
Thanks for the info. I've never used the diode test on my meter before so maybe I did something wrong but I got absolutely nothing when checking those pins. I tried the continuity test as well and also got nothing with that. Perhaps my RR is fried too.
from all indications your stator is had,I have found that the factory tests for the R/R are inconclusive especially if you are not really sure if you performed them correctly.

If you feel the R/R is bad which it sounds like it probably is you may want to consider going to the newer and cooler running,MOSFET type R/R ,there are several members on here who have and most have had nothing but good things to say about the upgrade.
 

·
1986 VN750
Joined
·
3,255 Posts
from all indications your stator is had,I have found that the factory tests for the R/R are inconclusive especially if you are not really sure if you performed them correctly.

If you feel the R/R is bad which it sounds like it probably is you may want to consider going to the newer and cooler running,MOSFET type R/R ,there are several members on here who have and most have had nothing but good things to say about the upgrade.
I definitely agree with denny that testing the R/R is not exactly the easiest the first time, but I find them to be conclusive during my testing. I guess your mileage may vary depending on your meter.

(Some?) aftermarket R/Rs test the diodes both ways, while the stock R/R has one way diodes (I am not an electrical engineer so if that is explained incorrectly.. sorry).

Personally, I did not go the MOSFET route, but not because I have anything bad to say about it. A pulled R/R off ebay was cheaper and I was broke ;). I went for a stock R/R that was in good condition off a Ninja 600 (same part#), and I get the full 14.5v charge @ 2,300rpm. No charging is occurring at idle, which the MOSFET can do - big bonus there. Isn't the downside to the MOSFET the fact it does not have the 6th cable that turns it off when the bike is shut off? I think I read about current draw at all times, so a few installed some switches. Worth a search on the boards at least.

What I can say is do not buy some cheap-o new R/R. The one I replaced was less than 6 months old apparently, seems to be the cheaper $60 one sold on eBay from overseas.

I would possibly research a little bit on the diode testing and see if you can get some verifiable results. My third stator connector on the cheap-o r/r tested bad (solid tone), and two of the three tested bad on the old stock r/r that was oddly still mounted on the bike (one solid tone, one infinite reading). The used one I ordered on eBay passed all the tests first time around, and is working great.


I guess the real question is, could a bad junction box end up frying the r/r, which in turn, killing the stator? *CSI Glasses*:loser1:
 

·
Premium Member
Joined
·
5,236 Posts
I guess the real question, is could a bad junction box end up frying the r/r, which in turn, killing the stator? *CSI Glasses*
I would say it is a very strong possibility but the way his post reads I lean toward the head light fuse blowing when he plugged it back in with the bike running,and I understand about the being low on funds when you buy a R/R,The only warning I would give is do not buy one of the cheap aftermarket ones,I too bought the original type from ebay and it was the Shindegen oem brand,as for the current draw problem ,I don't think that the members that ride their bikes on a regular basis found this problem,it is so small ,but one member that had left hie bike sitting for an extended period of time found this problem.A battery tender that is used for prolonged down times would alleviate this problem,along with being a good idea whenever your bike is parked for extended periods no matter what regulator used.But if you want to eliminate this this drain, find one wire that only has voltage on it with the key on and wiring it into normally open relay to run your charging wire through to the battery would open the circuit with the drain on it unless the key is on,Not a big deal and about eight buck at any automotive supply,good luck whichever route you take.
 

·
Registered Badass
Joined
·
102 Posts
Discussion Starter #7
Yeah the RR I have on there now is actually from a Ninja. And the junction box I just ordered is also from a Ninja. Hell I think the engine and the frame are probably the only parts left not from a different bike/year hehe

The headlight fuse is still good. It was the first thing I checked. In fact I was surprised it was still good after that. But perhaps the relay is what died instead of the fuse.

Money is pretty tight right now but I'm still leaning towards a MOSFET. I don't want to have to replace the RR a third time. The minimal drain is not a big deal to me as I have a reliable trickle charger. Although I'll probably wire it to a switched power source anyway.
 

·
Registered
Joined
·
458 Posts
Cut and dry, If your stator leads are shorted to ground and the stator wires are in good condition or stator is bad and needs replaced. Putting a new R/R without replacing the stator is a waist of time. If you Replace that R/R with a shorted stator you could be buying another R/R later.
I would replace both. I went with a mosfet R/R from roadstercycles and Tim parrot to have my stator rewound (much cheaper and he uses better materials-so i was told). Havent had any problems since.
The first sign I had when my stator went was my headlight not working.
 

·
Linkmeister Supreme
Joined
·
7,960 Posts

·
1986 VN750
Joined
·
3,255 Posts
From what I have learned from this forum, it sounds like the stator is shot.
Here is a link to tim parrott`s stator rebuilt service on ebay:
http://www.ebay.com/itm/motorcycle-stators-rebuild-service/180382187937?_trksid=p4634.c0.m14.l1262&hash=item29ff9dc1a1&item=180382187937&pt=Motorcycles_Parts_Accessories&vxp=mtr

He comes highly recommended by many previous customers.
I'm also just backing up Hoss that absolutely everything I have read about the rebuild service indicates they are top notch.

The whole R/R discussion was just centered around that it could have caused the stator to fail if it had gone, but the stator definitely indicates bad. Just make sure the rest of the components in the charging system are good prior to starting up the bike with the new or rewound stator so that it does not incur any damage.:smiley_th
 

·
Premium Member
Joined
·
3,027 Posts
After spending many hours working on a mid '80s Goldwing charging system, finally giving up and going with an externally mounted car alternator (unfortunately not possible on the Vulcan), the Vulcan's charging system seems so simple now. Your stator is definitely bad. I recommend one from Rick's Motorsports. Not familiar with Tim Parrott, so those may also be good.

You will need to pull the engine to replace the stator. If you choose to do the modification to the stator cover so you can replace the stator without pulling the engine, PLEASE pull the engine the first time, and get that cover far away from it before doing any cutting and grinding. You most definitely don't want your engine full of metal bits. You will have a lot bigger problems than a stator if you get metal inside the engine.

I recommend you go with a stock Kawasaki R/R. I have put 151,000 miles on them on 2 Vulcan 750s without a problem. I have to recommend against the MOSFET R/R, but that is my own personal opinion, it's up to you.
 

·
Premium Member
Joined
·
4,778 Posts
Quite a few members have done the stator cover mod with the engine in place and haven't reported any problems so far. I'm going to be doing mine that way soon. Several members have reported that new stators (can't remember if it was from Rick or Electrosport?) have failed within a short time. Tim Perrot does a good job and uses good quality materials. That's where I sent mine for rebuilding. Excellent product, and cheaper than buying new.
 

·
Registered
Joined
·
1,623 Posts
Several members have reported that new stators (can't remember if it was from Rick or Electrosport?) have failed within a short time. Tim Perrot does a good job and uses good quality materials. That's where I sent mine for rebuilding. Excellent product, and cheaper than buying new.
I am one member who bought a Ricks stator and the wiring at the stator melted down and shorted to ground after 400 miles. Pissed don't describe how I was. CHEAP wiring to say the least. Had put on a mosfet R/R and a new MF baterry at the same time. Sent the original stator to Tim Parrott and it has held up great and it really just looked to have been built so much better than any other one that I looked at. Thats where I would spend my money. Here is a picture of the Ricks melted special. It has aluminum bust on it from the cover mod.http://www.vn750.com/forum/picture.php?albumid=308&pictureid=1853
 

·
Premium Member
Joined
·
3,027 Posts
I still cannot recommend doing any cutting or grinding on that cover without removing it first, but it is up to the owner, as it is the owner who is taking the risk with their bike. Bits and pieces of metal do bad things to the inside of an engine.

As for the stator from Rick's, I have never used one, but they come highly recommended on many forums, including several different Goldwing forums. The Goldwing '75-'87 is another bike where the engine has to be removed to replace the stator. But if Tim's stators are known to be good, then go with that one.

As best as I can remember, I have replaced 2 motorcycle stators in my life, and I believe both of them were oem parts. Neither one required the removal of the engine. One of them was on a Suzuki GS850, not positive about the other one.
 

·
Premium Member
Joined
·
4,778 Posts
I believe Ricks stators were good quality at one time, but heard he switched to a Chinese made product, and the problems began.
 

·
Registered Badass
Joined
·
102 Posts
Discussion Starter #16
Thanks for all the info guys. I truely love this place!

I just installed a new MOSFET (shipping from roadstercycle.com was unbelievably fast!) and a junction box off a Ninja 600.

As expected there was no change but at least now I feel like I can replace the stator without fear of it going bad from a faulty part elsewhere.

I'll most likely be doing the Tuxedo mod. I just have to wait for the money fairy to come along and buy me one.
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
samshen reported as spammer.
 

·
Registered Badass
Joined
·
102 Posts
Discussion Starter #18 (Edited)
I'd like to thank everyone who chimed in on this thread. The problems have been resolved after doing the Tuxedo mod and replacing the MF battery.
I found out that the headlight won't come on if the stator isn't outputting correctly to the headlight relay. So once I hooked up the new stator, the headlight began working as well.
The MOSFET is kicking ass putting out 14.5V at idle too! Seeing that made the long struggle well worth it. Not only is the bike fixed, it's been upgraded! And should the stator ever burn out again it will be trivial to replace it.
 
1 - 19 of 19 Posts
Top