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Will a bad battery give a low reading @ 5K rpm?


VFRFahnder

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'97 VFR750

I had a loose battery connection and fried my R/R.

As a result, I ran the battery stone dead and ended up stranded.

I replaced the R/R with a Rick's, installed a VFRness and a battery monitor for the dash.

I got over 13.6v @ 5,000 rpm after installing everything.

Now, a month later, my battery won't charge while riding. I am getting 12.8v @ 5K at the battery.

The battery is at least 3 years old maybe older (bought the bike used).

Can a battery in poor condition cause this or is now my stator probably suspect?

**Update - I found out the battery is 4.25 years old**

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With a battery that old, I'd probably replace it anyway. Testing the stator is pretty easy. Unplug the stator connection on right side of motor (should be just above right side engine cover). If you have a multimeter, test all combinations of wires with one another while the bike is running. Should test out at around 60+ volts on all combinations at 5K.

Chuck

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With a battery that old, I'd probably replace it anyway. Testing the stator is pretty easy. Unplug the stator connection on right side of motor (should be just above right side engine cover). If you have a multimeter, test all combinations of wires with one another while the bike is running. Should test out at around 60+ volts on all combinations at 5K.

Chuck

That's 60v AC not DC, correct?

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I eventually replaced my whole charging system. The last thing I replaced was the stator. It was hard to detect for some time. It would test out fine when cold. However, after the bike got hot was when the stator would start failing and I would get inconsistent readings on my volt meter.

Chuck

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Well, after disconnecting everything, calling Yuasa, load testing the battery and checking all of the connections with my DMM once again, the damn thing puts out 13.6v @5K.

Go figure.

Joshua at wiremybike thinks I had an incomplete connection somewhere.

Hopefully, it's done doing this.

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Well, after disconnecting everything, calling Yuasa, load testing the battery and checking all of the connections with my DMM once again, the damn thing puts out 13.6v @5K.

Go figure.

Joshua at wiremybike thinks I had an incomplete connection somewhere.

Hopefully, it's done doing this.

Ha Ha. check my resolution here: (skip to post 27 if you like)

http://www.vfrdiscussion.com/forum/index.php/topic/69427-volatge-question/page__fromsearch__1

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Well, after disconnecting everything, calling Yuasa, load testing the battery and checking all of the connections with my DMM once again, the damn thing puts out 13.6v @5K.

Go figure.

Joshua at wiremybike thinks I had an incomplete connection somewhere.

Hopefully, it's done doing this.

Ha Ha. check my resolution here: (skip to post 27 if you like)

http://www.vfrdiscus...__fromsearch__1

I believe you are correct, my MD friend.

I went for a ride today and after ten minutes I lost my second green light on my LED voltmeter.

And then at idle, I got no green light at all. Everything was fine on the ride out. One green at idle and two at speed.

When I got home, I was only putting 12.5v at 5K - not good.

I will email Tightwad and see what he says. I just bought a R/R from him two months ago.

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did you replace the battery already?

my symptoms were like chucksters, 15 minutes and resistance would build up in my fried ass stator. But you will likely need a battery anyway

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did you replace the battery already?

my symptoms were like chucksters, 15 minutes and resistance would build up in my fried ass stator. But you will likely need a battery anyway

Actually, I took it to Pep Boys where they tested it. It puts out 258 CCA at ambient temperature. I called Yuasa and they said the battery is still good. Even tough it is 4 years old (Yuasa told me the production date) it has only 3K miles on it and spent its life on a Yuasa Smartshot.

I have a few emails in to Tightwad about my stator but have yet to hear from him - he must be busy or out of town.

So you replaced the stator? Did you get OEM or aftermarket?

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I recommend that you do a continuity/coil resistance check of the stator wires. Use an ohmeter and connect to the same wires that you did for the AC volt test. Should be 0.1 - 1.0 ohms at 68f. You connect the ohmeter to two pairs of wires at a time. Then connect to one wire and ground. Reading should be infinity.

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I recommend that you do a continuity/coil resistance check of the stator wires. Use an ohmeter and connect to the same wires that you did for the AC volt test. Should be 0.1 - 1.0 ohms at 68f. You connect the ohmeter to two pairs of wires at a time. Then connect to one wire and ground. Reading should be infinity.

I appreciate the info. In fact, I did that and it all passed.

My question is - Should I maybe do this after a warm-up ride?

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Honda says to do it cold but sometimes electrical stuff fails when hot. I would suspect that the ohm readings would be somewhat different when hot but they don't quote any hot figures. The continuity test would allways be infinity. If one of the windings have shorted to earth you will get a reading.

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Okay - the stator checked out good doing the ohm, continuity and AC tests with a warmed-up engine.

So I spoke to the "Rick" of Rick's Motorsport Electrics and he said that he would test the R/R if I send it to him.

I boxed it up and took it to the post office. We'll see what happens next.

I've got to say that this blows. :mad:

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If your battery is good and you've got a relatively new R/R, I'm betting it may be the stator is shorting itself after it heats up. I don't just mean warmed up, I mean hot. I could ride mine 10 miles before it would start giving me the low readings. So was the case with mine. My stator was original OEM and I replaced it with a Rick's. Josha (wiremybike.com) actually helped diagnose my problem for me. Haven't had any problems since.

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If your battery is good and you've got a relatively new R/R, I'm betting it may be the stator is shorting itself after it heats up. I don't just mean warmed up, I mean hot. I could ride mine 10 miles before it would start giving me the low readings. So was the case with mine. My stator was original OEM and I replaced it with a Rick's. Josha (wiremybike.com) actually helped diagnose my problem for me. Haven't had any problems since.

10-4, Chuckster. I seem to have the same symptoms. I am in touch with Joshua right now. I guess taking the least expensive route first (getting the R/R tested) makes sense.

If it tests good then I guess it's time to open my wallet more.

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Chuckster - our stator's must have been related. I could make it 15 minutes on the bike before the resistance would short the stator out. Symptoms got gradually worse but I would get good readings and could not diagnose it because I was testing it cold.

When the shop pulled it - this is what they found.......

post-21159-0-35517800-1322870004.jpg

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I know right? Everyone was laughing at me when I called the fire department due to the amount of smoke coming out from under the gas tank, not anymore.

It tested out fine and Kaldek spent about 45 minutes with me trying to figure out WHY I was having problems!!!

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That stator pic is very typical once they are shot, smoke under your tank is coming from somewhere else, Ive not seen a wet stator billow smoke out of an engine. I guess its possible but through a vent line. Did you also have burnt wiring around the RR?

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