Fried stator last fall - looking for cause

[TimC]

I'll preface this with an admission: I'm an idiot. Also, I'm not much of a mechanic.

I have a thread going about a 6th gen's sticky starter switch and headlights issue that ties into this, but figured it would be better to start a new thread about this issue. I wanted to write this up awhile ago, but am finally taking the time to do it now.

While dealing with a sticky starter switch last September, I sometimes had to repeatedly hit the starter button to get my 6th gen's headlights to pop on - flicking the button, not holding it down. When I opened up the housing I couldn't get to the switch itself in the housing due to the hazard switch being in the way. I cleaned it the best I could with electrical cleaner and compressed air. It wasn't 100% effective at first but the problem went away soon after.

During a trip back to Ohio from Kentucky later that month my bike died. I'm pretty sure I left the key in the 'on' position during a 5-minute map-check/water break, but in freaking out when the bike wouldn't start I can't remember for sure. Anyway, the bike wouldn't start. I had enough juice to cycle the fuel pump and managed to bump-start the bike and ride a few miles to the next town, keeping the revs up at a long stoplight just before I hit town.

I pulled into an auto parts store, pulled the battery, and had the shop charge it. Their tester said it was bad - and that's understandable considering that was the second time I had killed it. First time was last spring when I let the bike sit in my cold garage a couple weeks between rides without the battery tender hooked up. (I told you I was an idiot.)

Battery charged, checked operation with bike idling for several minutes, everything seemed fine. Was also fine at first stoplight a few minutes later. 20 or so miles down the road, however, the bike died as I coasted to a stop sign. I was able to bump-start the bike once more but had to keep the revs up constantly. The moment I let off the throttle the bike died again. (I had to have the bike towed, and that story is long, so I'll save you that.)

At the shop the bike was towed to, they replaced my fried stator and battery. I picked up the bike in late October or early November. I've put almost 2k miles on the bike since then and have had no problems, other than the starter switch is giving me problems again. Although I haven't had another major issue, I feel like I can't trust my bike for another long trip, which I really hate. This was the first time I was ever stranded. Being so far from home (5-6 hours travel time) made it that much worse.

So here is my question for the VFR experts: What caused my fried stator? Possibilities include:

-Having thumbed the starter several times last fall while the bike was running, in an attempt to get the headlights to come on.

-My best-effort attempt to fix the starter switch issue using electrical cleaner and compressed air, causing a short in the system. (Unlikely, I'm sure, but I have to mention it.)

-Leaving the key on, draining the battery, then bump-starting the bike.

-An "overcharged" recharged battery.

-It was just the stator's time to go at almost 59k miles. (This was a local shop's opinion.)

-2 or more factors above.

-All of the above.

Like I said, I can't be certain I left the key 'on' during that stop. All I can really remember is the bike wouldn't start and I was several hours from home. I probably did leave it on, but if I didn't maybe the stator had fried while I was riding for the previous hour and that drained the battery.

I want to trust my bike again for a trip this summer but I'm having a hard time doing it. Also, because the starter switch is acting up again, I want to be sure to get it fixed (or even replaced) now before anything else happens, including me trying to fix it and causing another problem. (That's probably unlikely, but I can't rule it out completely.)

Thanks an advance to my VFRD family for the help!

[Guest]

I'll preface this with an admission: I'm an idiot. Also, I'm not much of a mechanic.

I'm pretty sure I left the key in the 'on' position during a 5-minute map-check/water break, but in freaking out when the bike wouldn't start I can't remember for sure.

I love you honestly, and humor

I wish I could help, but, well, me and electrical issues go together like oil and water.

Good luck!

[TomP]

The charging system is a three-legged stool -- stator, battery & regulator/rectifier. And unfortunately, when one leg goes, there's a good chance one or both of the other legs get taken out as well.

You've had two legs break. I'd triple check the R/R and all associated connections.

[timmythecop]

Prolly died of old age. Mine went at near 50,000 and I think the average lifespan is about that. I sometimes have to jiggle my starter button rearward because of some stickiness, buy it's habit now. I don't think the starter probs have anything to do with the stator.

I was worried about my charging for Tmac after some failures, but there was no problems. Woot.

[Rice]

I agree with the bikek shop - Old age.

However, I would test the charging system to regain trust.

At the very least, test the charging voltage and the condition of all Stator/RR plugs. That should help regain confidence.

As step 2, I'd upgrade the charging system. It isn't difficult. Three main things need to be done: 1 - Add ground to the RR 2 - Route monitor wire directly to the battery and 3 - Eliminate the plug between Stator and RR and just solder the wires. I've done it on mine and so far so good.

[spud786]

59,000 mile is above average for most motorycle stators, the average is below 50,000 mile, the vfr Oem stator falls in the above average range for motorcycle stators, I only got 56,000 mile off my first VFR stator.

Really a good AGM battery will stay full charged 2 or 3 weeks with no issue, as long as its ridden a few hours to charge every couple weeks. Its really when you go a couple months, and start it up for 5 minutes in between, the battery never recharges.

I rarely use a Tender, but My but is ridden several hundered miles every week, but there have been a few times Ive gone a couple weeks, and tested the standby voltage, still holding over 13 volt. The AGMs when they get weak will start reading below 12.8 volt within a couple hours after recieving a full charge. Thats when you know its weaking and time to look towards a New one.

[TimC]

Thanks for the replies, everyone. I dropped a laundry list of maintenance items at the local dealer yesterday, waiting for estimates now. One of the items is checking/testing the R/R. If I were a better mechanic I'd do it all myself, but my abilities are limited, as is my time.

[TimC]

I've been thinking about it some more, and I'm beginning to think what I said above may be true - that the stator fried while I was riding normally, and that it was already fried when my bike wouldn't start, whether I left the key on or not.

I don't think my bike was running strangely before the last stop before my bike wouldn't start again, but I think it's possible the stator failed during that last stint and my continued riding kept the bike running until that last stop.

Regardless, I'll have the electrical system checked out during a shop visit next month. Thanks again for the replies, folks!

[spud786]

Stators begin to burn, then they get weak for a time period before actually going out completely. When my vfr stator failed , I had 14.7volt charge out of the driveway, sometime within the next 30 minutes , it just cratered. I was having to much fun and didnt notice the readout, till my RD squealed Low voltage. That atleast made me turn around and head to the house. Unfortunately I was already at 10.5volt, so I only made it about 4 or 5 miles, lost the dash , then the fuel pump, then coasted to a stop dead in the water.

So the vfr will run okay till about 9 volt or so, Luckily the battery recovered, so I didnt have to replace that.

But I had 2 weeks of prior warning, when I noticed my charge voltage was 14.2 and never varied, which was really abnormal for my VFR, but still not out of spec, so I ignored.

[TimC]

I've thought about installing a voltmeter but haven't done much homework on it yet. This was the first time I'd had a major electrical issue, and I don't have any powered accessories, so I never worried about it. Until now.

[MBrane]

Actually powered accessories will help the charging system as long as you're not taking out more than you're putting in. Stators die due to the heat cycles, and vibration of life inside the engine cover not the amount of current you draw from them.

[spud786]

Its probably safer just to replace the stator sometime once over 50,000 mile , its days are numbered for sure. I think I heard someone make it to 80,000 mile, but only one.

THe voltmeter is a value, otherwise you are clueless as to whats happening on the road with your charging system, that will leave you broke down in the middle of no where. Look at my case, I definately would have been much further out, well atleast 4 or 5 mile.

[MBrane]

Its probably safer just to replace the stator sometime once over 50,000 mile

I consider 40K to be a much safer number. I treat it as a consumable item just like batteries, tires, brake pads etc.

[TimC]

Its probably safer just to replace the stator sometime once over 50,000 mile

I consider 40K to be a much safer number. I treat it as a consumable item just like batteries, tires, brake pads etc.

OK, so since mine was replaced at 58k mi, I should be good 'til at least 100,000 miles, right?

[kaldek]

Like everyone else has said, get a voltmeter. The first sign of a dud stator is that it puts out low voltage at idle when hot, and then it starts to stop putting out decent voltage until 3,000rpm.

And then one day it just goes dead. Suddenly. Mine did that while I was synchronising the throttle bodies and idling the motor.

What basically happens with them is that the insulation on the wiring degrades due to heat. When it degrades, it short circuits the winding and when that happens a winding which may have been, I dunno, 100 feet long is suddenly 1 foot long. Ergo, no energy created when a magnetic field (the rotor magnet) goes past.

You can rewire a stator, but it's a bitch of a job and you need to make sure you use the correct type of wire with the right kind of insulation, and then you have to cover all that in heat resistant epoxy. Not for the feint of heart!

Also as has been said, it's better to draw more current out of your stator than to not. This is because the less power taken from it, the more the regulator shunts the power the stator generates back into itself. This causes heat, which causes insulation to degrade faster.