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Yet Another Charging System Issue

3K views 26 replies 7 participants last post by  Odin'sRavens 
#1 ·
Found my battery dead last week and started poking around for what to check. Bike is an '05 with about 12.5k miles on it.

I hadn't been watching the volt meter and it turns out I was getting nothing to the battery while running. I pulled the r/r and checked the continuity/ohms on the pins and it's not reading anything. I checked the continuity between the yellow stator inputs and they seemed ok but they also had a reading to the chassis. Two of the pairs seem to put out decent AC voltage and the other was lower (measured at low rpm idle).

At this point, I'm working on the assumption that the r/r is dead and the stator is shorting.

The motor/electrical haven't been modified in any significant way.

Based on the info I found here, I ordered a "super mosfet kit" from roadstercycle. I have questions about the rewiring bypassing the harness as it seems to leave a wire (was it load splitting?).

I do have the Clymer book for reference.

Also, I'm not sure of the current "best practices" when it comes to the stator. I saw the $450+ kit from TOC but it doesn't include the stator. I might have the resources to do the machining on the cover and get one of the plate kits from gcextreme or similar. Stators from partzilla are currently $340.

I'm hoping a new r/r will get it to run through the end of the season (unless that is a really bad idea for some reason).

If I get into the motor far enough to get the cover off, what else should I be doing while I'm in there?

Thanks in advance for the support and for keeping this great source of information alive!
 
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#2 ·
I'm not clear about your question on wiring the new r/r.

Thorn recently uncovered a possible misprint on the test procedures for the r/r in the repair manual. Maybe he can shine some light there.

If the stator is testing defective, the new r/r won't get you through the season, or the first ride. It has to charge the battery or you're going to get stranded on the side of the road.

Check the damper bushings while you're in there.
 
#15 ·
Check the damper bushings while you're in there.
You talking about parts 92075-1747 and 92075-1748? Partzilla has them in stock and I can get a whole set for $60 shipped.

I did a little searching on here and it seems that if they fail it would be really bad for the motor. Should I just change them while I have the cover off? I suppose they cannot be changed through the modified side cover stator hole from TOC.
 
#3 ·
So, the R/R should definitely have continuity between a lot of the pins though the ohm values listed in the manual may be incorrect (or only correct when measured using a multi-lead kawasaki-dealer device). Basically, there should always be a path from the DC negative side to all yellow wires, and always a path from yellow wires to dc positive. Path between yellow leads SHOULD exist, but might not depending on the exact circuit, and might not register until a certain voltage difference between the leads is achieved (more than 14v, more than the standard multimeter would be trying to push).

Connecting to a partially-shorted stator is probably death for the R/R. The stators and rectifiers seem to live or die together. Stator overheats if the R/R dies, R/R blows components if the stator shorts.

The mosfet R/Rs often do not need the brown "monitor" wire that the stock R/R does, so just the three yellow wires, the black/yellow ground, and the white V+.
 
#4 ·
I guess my main question is, what is the current go-to stator and side cover mod in 2019?

I'll test again after wiring up the new r/r this weekend (hopefully).

I was getting ohm readings from the yellow wires at the r/r to negative battery terminal. That's what led me to believe it was shorted out.
 
#5 ·
I just had my stator replaced, went with an OEM stator. Made the decision to go through that once and that’s it because it hurt my wallet. I have no place to do a job like that. If I read the thread right you said your stator is testing continuity to the chassis. If that’s the case it’s shot. So that’s probably going to need to be replaced 1st or you’ll fry a new R/R. And even though it’s pricey the TOC stator cover plate is a good bet. All depends on how much you love the bike.
 
#7 ·
Thanks, I saw that one. If I end up doing the work myself, I'll probably go that route. I'll still remove the engine though to prevent contamination.

If I take it to a shop, I'll not want to interrupt them to say "give me that cover when you get it off and i'll cut a giant hole in it".

I figure while the engine is out I should do the ACCT to MCCT conversion as well.

So I'm thinking about buying everything TOC has and selling him my old cover.
 
#9 ·
I didn’t have an option to attempt this myself, no garage or space in the city. Having that modified plate would definitely bring peace of mind, but I’d be really hesitant to cut it while still on the bike. Yeah, people have been successful with it but I know my own luck.
 
#10 ·
So I got the R/R in, cut the stator wires off before the original crimps. The readings at around 2kRPM between the 3 pairs go something like 8VAC, 18VAC, 24VAC. Again I checked from this point to the negative battery terminal and they all had continuity.

The stator is definitely messed up. The rick's coupon for 10% off went up today (FREEDOM). It's good for a few days for online orders only. Using that, I ordered a new stator for $130 shipped.

Just because, I went ahead and wired everything up (including blue-wire headlight relay bypass). I left the battery to charge overnight and checked the charging voltage using my voltmeter/USB ports. It reads a bit low so these numbers will be a little fudged.

At bike off: 13VDC
At bike idle: 12.3VDC
At bike 4kRM: 13.3VDC

So it is putting out a small amount of charge. You think it will damage the R/R if I run it?

I also bit the bullet and ordered everything TOC had. I still haven't decided if I'm going to pay someone to tear into it since I do have some space available to do the work.

At this point I'm waiting on parts.

Did I see a simplified stator removal procedure that doesn't involve completely tearing down the engine? I'll do a search again but if someone knows the thread, that would be appreciated.

Thanks everyone and happy independence day! Be safe out there.
 
#11 ·
Sounds like you got everything you need. There’s a procedure to “tilt” the engine as opposed to completely removing it. The big concern I’ve read is to make sure the shifter is clear of the frame because if it gets bent you’ll be even more f@&ked. You’ll still need to remove most of the same things but I’ll let the others who’ve done it weigh in there.

As to riding with a shot stator, I think it’s prob a bad idea, a path to ground that shouldn’t be there is a short. Could fry the R/R, and at the very least will overwork the battery which prob won’t last long p/ride and ultimately will need to be replaced. So you’ll be adding that cost to your total spend.
 
#12 ·
Thinking of it electrically If the stator isn’t connected it shouldn’t hurt the R/R, but most importantly you’re asking to get stuck when that battery loses its juice. I didn’t ride far before my bike stalled out and my portable jumpstarter didn’t have enough. Had to wait for jump, just for it to stall again a mile or so from home.
 
#13 ·
#18 ·
Glad you found my thread, I hoped it would be of use and was about to post it myself.

The dampers are a good idea while you're in there. I pulled my engine to replace them, but ultimately I didn't really need to, I think I was just being paranoid about vibrations. Regardless, the parts list I posted was all inclusive for every part disturbed in disassembly.
 
#20 ·
I don't know where to get a good stator anymore. I got mine from TPE, but they are no longer in business. It was a rewound one, and I sent them my old burned up one so they could rewind it and sell it. If there is one thing I have to say about replacing stators, it is DO NOT UNDER ANY CIRCUMSTANCES install the tuxedo mod with the cover on the engine. You will fill the engine with metal shavings. It would be a shame to destroy a 12,000 mile engine in a 2005 bike just to save a little trouble or money. When I bought my '97 a few months ago, I took the 3 screw cover off to make sure it had not been cut up. The TOC cover is ridiculously expensive, but if you have a like new bike, and don't plan to modify it, it might be worth it. As expensive as it is, it won't seem that way if the stator fails again. I also highly recommend their MCCTs, I have a set myself.

The Vulcan 750 is getting so old and are so cheap now that many owners are chopping them up and making a lot of modifications to them. I have bought 2 brand new ones, left both mostly stock except for defective parts like the cam chain tensioners, and got 108,000 miles out of the last one. It failed due to a broken cam chain, which might not have happened if the oem tensioners weren't defective. I may have damaged the chains and guides early on when the oem tensioners failed.

I also highly recommend removing the engine completely the first time. It is so much easier to get to everything, and you can check/replace the balancer dampers at the same time. It took me about 6 months to replace the stator because other things kept getting in the way. I practically stripped the whole bike down to make it easy to get the engine out. I had a home made wooden dolly I built to remove air cooled VW engines with, I just rolled it under the engine, put shims between it and the engine till it fit tight, removed the mount bolts, and rolled the engine out from under the bike. By removing the front manifold, I was able to get it out without removing the front bevel gearcase.
 
#21 ·
I'm having trouble locating specifics on how to get at those dampers behind the stator.

The bike says to open the right side and work from the other end. (Unless I'm reading that wrong.)

From what I gather, I have to remove the rotor and a wheel to get at them. What is the best way to change these things? Can it be done without opening the right side?
 
#23 ·
That was a hard two days work.

I probably should have pulled the motor all the way out instead of swinging it to the side with a ratchet strap. I think the main issue was the stock air system jamming everything up.

Re meshing the drive shaft was miserable. Getting it apart was a pain but putting it back together was worse.

My original damper bushings were falling out so it was probably a good idea to replace them. My rotor was really stuck on there too.

At this point it is all back together and running even if a little rough. I need to adjust the MCCTs. Any advice on doing that? I don't know how you are supposed to do the right side since there is no room to put wrenches on anything over there.
 
#24 · (Edited)
I have the TOC MCCTs. Warm/ride the bike until normal operating temp. Install the front(left) MCCT. Turn the adjuster in until you feel slight resistance. Snug the lock nut. Start the bike. loosen lock nut and turn adjuster in until you get the least clicking. Tighten lock nut. That's the easy one

Stop the engine. Remove the coolant bottle on the right side and let it hang upright. Use something to secure it. Install the MCCT and initially adjust the same way. Start the bike and finish the adjustment. Rev it a bit and listen. When it sounds "right" check and retighten the lock nuts. Hold the adjuster with a wrench to keep it from turning, install the coolant bottle and ride a bit

Use 2 17mm wrenches.

Hard starting/bad idle, too tight. Still clinking, too loose.

You'll probably hear a "hooing" sound of the chains going over the guides. I'm told this is normal. Just how loud is "normal" I can't say as mine is the only VN750 in town and have nothing to compare with.

Also! While you're installing the MCCTs and have the ACCT out, don't let the engine turn over! You might jump timing.
 
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#25 ·
So I already have both of them installed. (Started with the finger tight and back off a half turn.)

The first start after putting the motor back together and refilling the fluids was low RPM, no high idle like it usually did. Wouldn't idle without choke.

I backed off a little more on both and got the high idle like I used to get and it idles without choke.

I was letting it idle and checking the charge (which was about 14+V at 900RPM). I opened the throttle a little bit and held it at 2kRPM. It was sputtering a bit and then at 3kRPM it was OK again.

By sputtering I mean running OK with occasional spit/dip in RPM. It just wasn't smooth.

I'll unmount the coolant bottle and hang it from the frame, reset the MCCTs to finger tight - .75 turns, run it around the block, and then start fiddling with it.

Unless you think I should re-install one of the ACCTs and do them one at a time.
 
#26 ·
If they're in leave them in.

After installing mine and feeling the chain with the adjusters. I tightened the lock nuts and started the bike and let it warm while I removed the coolant bottle. One at a time I turned the adjusters in until I felt the chain wasn't banging against the adjuster. Did the same for the other one. Then rode the bike a bit to normal operating temp.

After it was hot, I adjusted the mccts to get quietest chain noise. I don't think you should get all the clink out. I'm told these are noisy engines.

Also! just above the mccts you'll see a large chrome cap that screws in/out. Behind these caps are springs that control the chain guide tension also. Over time these seem to get weak. I removed these and put in a small washer, then the spring and reinstalled. This seemed to help also.
 
#27 ·
I took it out for a ride this evening after fiddling with them in the driveway. Lost power when I hit third. I came back and loosened them a bolt face and it seemed ok. It felt like there was a little more engine breaking than usual and was working a little harder. When I got back, I loosened them another bolt face.

I see the large bolts with a chrome flange thing there above the tensioners. Hopefully I don't need to mess with them since I only have 13.4k miles on the bike.

Thanks for the help, all. It was immensely helpful.
 
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