SuzukiSavage.com - Battery dying when engine hot

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Battery dying when engine hot
08/31/15 at 15:18:56

Good day.
Love this forum. First time poster, long time lurker.

I have a 1986 Suzuki Savage.

It is in decent shape. I recently followed the steps to fix the dreaded Savage oil leak from that loose plug. Thanks for that.

The new problem, which when I think back on it, has happened since I got the bike. I have only had it for a month. I am a new rider. The first few rides I did were short. The longest of which, about an hour included me making 1 stop and then continuing. As I was gearing down to enter my driveway the bike lost power and stalled. After talking to some friends, they tested my battery and said it was dead. No problem.

I bought another battery. By this point, I had finished my motorcycle training course and was about ready to do longer rides. The first ride was a bust. I went to a buddy's house, then to get a coffee, then went to get gas. After I filled up, the battery was dead. Needed a boost.

Next ride; left my house, rode to a meeting spot 15 mins away. waited about 20 mins for my friends. Bike started fine, rode about 10 mins til one buddy had some idling issues. Turned off bike, he fixed his, and then we went to leave and my bike was dead again. Needed a boost. Proceeded to a coffee shop about 15 minutes away, had to bump start it. Half way home it died again. Wouldn't bump. Was getting dark, called a buddy and loaded bike up in his truck.

I tested the battery with the multimeter, on and off and while revving. seems OK in that sense. Remember i'm a newb btw lol.

Told another buddy about this problem and he pointed out that the problem seems to happen after bike gets hot, it drains the battery. We let the bike get cold, it started up magically after the battery was recharged. Sounded great. revved nice. Then we killed the engine and let it cool. Put a heat gun on it for a few minutes and tried starting it. It chugged and really did not sound like it did 5 minutes earlier. So clearly when hot something is causing the battery to drain.

This being the extent of my knowledge I'm now turning for some input from the more experienced people.

Any tips/tricks/things to try would be most appreciated; as well if I need to provide more info, just ask.

Thank you. Roll Eyes

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« Last Edit: 09/01/15 at 03:34:50 by Dave »

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verslagen1

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Re: Battery dying when engine hot
Reply #1 - 08/31/15 at 15:32:23

daincitydave wrote on 08/31/15 at 15:18:56:

i tested the battery with the multimeter, on and off and while revving. seems ok in that sense. remember i'm a newb btw lol.

The output is supposed to be 14v (or thereabouts) at 4000 rpms (or thereabouts)
So when you tested it, what volts at what rpm?
4000 rpm is about what you'd do at 50 mph.

Not to many problems while hot specifically, but yours is an '86 so age will breakdown insulation might be the problem.

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daincitydave YaBB Newbies Offline SuzukiSavage.com Rocks! Posts: 33	Re: Battery dying when engine hot Reply #2 - 08/31/15 at 15:38:23 yes i believe it was 13v while off and 14v while on and revving..
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Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: Battery dying when engine hot Reply #3 - 09/01/15 at 03:35:44 Where did you put the heat gun? That sounds like a scary thing to do. Test the voltage when it is hot and the bike won't start. That will help you determine if the problem is voltage related....or if something else is acting up when warm.
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Re: Battery dying when engine hot
Reply #4 - 09/01/15 at 06:53:00

You really need to test that battery voltage while you are having the issue.
Start it up ride it in circles if you have to, till it dies.
I don't think there is a time when a battery recharges itself when cold if it has died when hot.

Maybe the rectifier/stator?

Were you able to turn the engine over with the starter, when it died? did you have lights?

Or maybe the petcock not allowing gas flow.....

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chzeckmate Serious Thumper Offline Be the person your dog thinks you are Posts: 514 Houston, Texas Gender:	Re: Battery dying when engine hot Reply #5 - 09/02/15 at 00:42:12 I'd wager it's your regulator/rectifier. Cheap part. 5 minute fix. See ebay.
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Re: Battery dying when engine hot
Reply #6 - 09/02/15 at 03:55:33

chzeckmate wrote on 09/02/15 at 00:42:12:

I'd wager it's your regulator/rectifier. Cheap part. 5 minute fix. See ebay.

Well you will only confirm that with a test of the battery voltage when the problem exists. If I were having this problem.....I would invest in a cheap voltmeter so I could monitor the voltage while I was riding.

http://www.ebay.com/itm/12V-24V-Digital-LED-Display-Volt-Meter-Auto-Car-Cigar...

Or for long term.....a nicer one. (Wow -maybe not this nice....why do sellers list this bogus stuff).

http://www.ebay.com/itm/Auto-Meter-5991-ES-Electric-Voltmeter-2-1-16-in-8-18-...

This one is affordable:

http://www.ebay.com/itm/12V-Motorcycle-LED-Waterproof-Digital-Display-Voltmet...

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chzeckmate

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Re: Battery dying when engine hot
Reply #7 - 09/02/15 at 07:26:41

chzeckmate wrote on 09/02/15 at 00:42:12:

I'd wager it's your regulator/rectifier. Cheap part. 5 minute fix. See ebay.

Dave wrote on 09/02/15 at 03:55:33:

Well you will only confirm that with a test of the battery voltage when the problem exists. If I were having this problem.....I would invest in a cheap voltmeter so I could monitor the voltage while I was riding.

Yes, by all means. test first. I believe the op already mentioned he has a voltmeter and had tested the stator output at 14v while revving. Testing the r/r will take less than a minute and I'll wager it's bad given that the battery was new (tested good) and the stator is working. The fact that this is occurring while the engine is hot seems coincidental. It's is possible that there is a parasitic draw on the system somewhere else but my money's on the r/r.

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daincitydave YaBB Newbies Offline SuzukiSavage.com Rocks! Posts: 33	Re: Battery dying when engine hot Reply #8 - 09/02/15 at 08:26:08 i will ride around the block today until it dies and test it when it dies....i have seen the r/r's on ebay, yes cheap. thanks for all the tips. i'll try and report back!
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justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: Battery dying when engine hot Reply #9 - 09/02/15 at 09:07:40 How long would a fresh battery run without the rr charging? I'm not able to wrap my head around the battery getting warmed up by engine heat and go dead, Now would be a good time to. Build in a pigtail for a float charger. Makes for easy access to connect a bolt meter.
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Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: Battery dying when engine hot Reply #10 - 09/02/15 at 10:19:50 justin_o_guy2 wrote on 09/02/15 at 09:07:40: Makes for easy access to connect a bolt meter. A what?
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Re: Battery dying when engine hot
Reply #11 - 09/02/15 at 10:36:38

justin_o_guy2 wrote on 09/02/15 at 09:07:40:

How long would a fresh battery run without the rr charging?

The problem s more complex than that. The power from the battery isn't just passing through the r/r as if through plain old 14 gauge wire. If the r/r is bad then it will be causing a parasitic draw on the battery (essentially a short circuit). Depending on the draw it might kill the battery immediately or it might slowly suck the life out of it. This issue is frequently intermittent. You might go a day, a week, or even a month without issue and then suddenly the problem is back like a vindictive ex girlfriend. Eventually the problem is persistent and you stop wondering if engine temp, tire pressure, or whatever was playing a role in it. The op has had this bike a month and mentioned that this is a new problem to him, but I'll bet it wasn't a new problem to the po.

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daincitydave

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Re: Battery dying when engine hot
Reply #12 - 09/02/15 at 11:42:16

you could be right Justin.

just took it for a boot down my road. maybe 2km round trip. half way not leaving second I turned around. on way back got it to third then it started hesitating and eventually died. coasted into my driveway. checked battery right away. was 12. i revved up the engine and it went from 12 to 8 to 10 to 6 to 12.

before I left it was 13 while idling.

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thumperclone Serious Thumper Alliance Member Offline PGR rider riding with respect Posts: 6067 Grand Junction Colorado Gender:	Re: Battery dying when engine hot Reply #13 - 09/02/15 at 12:23:15 14 >15.5 vdc @ 5000 rpm
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justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: Battery dying when engine hot Reply #14 - 09/02/15 at 14:02:41 Dave wrote on 09/02/15 at 10:19:50: justin_o_guy2 wrote on 09/02/15 at 09:07:40: Makes for easy access to connect a bolt meter. A what? A bolt meter man, I've got a cold. Shoot,, gotta go scrape my one star off.. Drat. Blast you, Dave! You barmint..
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