Author Topic: Overcharge, or OK?  (Read 1547 times)

Offline 1Sourdough

  • Guzzi Hero
  • *****
  • Posts: 607
  • Location: North Iowa
Overcharge, or OK?
« on: July 17, 2017, 11:04:16 PM »
1993 Strada 1000 Playing with my mind . . .  again.

Intermittent start problem: Engine would turn over but would not pop.  Battery measured 12.5 or so with machine turned off.  After pretending to be flooded, and sitting for a few minutes to allow imaginary gas to vaporize, it would usually start.

It had not been run for about a month.  Tried to start last week, no go.  Put charger on, started right away.  "OK, battery low from not running."  Charger left on overnight.  Next morning no start, put charger back on and it started immediately.  Shut down, removed charger, no start.  Got it going, ran RPM to 3,000, Multimeter said 12.8~12.9 Volts.  OK, that sounds like battery or alternator.  The existing battery was an Odyssey PC925, which is alien to the parts people in this small town but the battery is easier and less expensive, so I replaced it.  The replacement is an AGM like the Odyssey, is an inch taller but fits the battery area, and has more power than the Odyssey. 

Now the engine turns over a little faster, and it starts immediately.  Well, charging circuits should read 13.5V to 14.6V at 3,000 RPM, right?  Whereas the old battery was reading 12.5 idle and just under 13V  at 3,000 RPM, the charge on this new battery was 12.8 a couple minutes after shutting off, and at 3,000 RPM it climbed slowly up to 15.3, which is when I shut if off until finding out if such a Voltage will cook the battery.  I don't know of any adjustments on this machine's Voltage regulator. Can a new, AGM battery stand that sort of charge without damage?

Fred
1993 Strada 1000, 1996 R1100RT, 1999 V11 EV
                            -30-

Offline Wayne Orwig

  • Guzzi Hero
  • *****
  • Posts: 12512
    • Hog Mountain weather
  • Location: Hog Mountain
Re: Overcharge, or OK?
« Reply #1 on: July 17, 2017, 11:08:35 PM »
15.3V will cook the battery dry. Find out what that is about.

The no start with weak voltage sounds like you need to inspect/clean/gap/replace the spark plugs.
« Last Edit: July 18, 2017, 06:36:57 AM by Wayne Orwig »
Scientist have discovered that people will believe anything, if you first say "Scientist have discovered...."


Online Kiwi_Roy

  • Guzzi Hero
  • *****
  • *
  • Posts: 6768
Re: Overcharge, or OK?
« Reply #2 on: July 18, 2017, 12:28:18 AM »
I suspect you may have a flakey Voltage reference due to a bad contact between battery + and the regulator's black reference wire.
If it's low it will fool the regulator into thinking the battery needs charging.
Resistance in the ignition switch or a bad contact somewhere between battery + and the regulators black wire.

http://www.thisoldtractor.com/guzzi007/schematics/1994_Strada_1000_Type_1.gif

Measure the Voltage reference between the regulator's black wire and chassis, you can do this without starting the bike, just turn the key On
Just slip the Male/female connector apart a wee way to expose the male pin connecting to the loom red/black wire. Try switching the key slowly to see if it's erratic (dirty contact), turn the switch off and on several times, is the Voltage consistent?

Check the second fuse down, is it nice and tight?

BTW it just so happens the same ignition switch contact also feeds the coils via fuse 1, perhaps that's the reason for hard starting, low coil Voltage
Clean and lube the switch with fresh Vaseline

You can measure the Voltage drop directly between battery + and the reference

BTW, the same ignition switch contact feeds the coils, perhaps that explains the hard starting as well.
Clean and lubricate the switch with fresh Vaseline.

Provide a good ground to the regulator with a short wire between the case and an engine bolt.
« Last Edit: July 18, 2017, 05:27:49 AM by Kiwi_Roy »
72 Eldorado
07 Griso 1100

Moto Guzzi - making electricians out of riders since 1921

Offline pat80flh

  • Weekend Warrior
  • ***
  • *
  • Posts: 212
  • Location: Finger Lakes area of NY
Re: Overcharge, or OK?
« Reply #3 on: July 18, 2017, 04:41:13 AM »
I'd bet your regulator is cooked, from trying to keep that old crappy battery charged up.
00 Bassa
80 FLH (in rehab)
84 V65C
75 850T prject

Offline Guzzidad

  • Guzzi Hero
  • *****
  • *
  • Posts: 519
  • Location: Tampa, FL
Re: Overcharge, or OK?
« Reply #4 on: July 18, 2017, 07:47:32 AM »
   Same thing happened to my bike. Just try this: remove (or unplug) your headlight. Now check voltage with the bike running. Has it corrected itself? If so, PM me. Easy fix.

Online Kiwi_Roy

  • Guzzi Hero
  • *****
  • *
  • Posts: 6768
Re: Overcharge, or OK?
« Reply #5 on: July 18, 2017, 09:18:17 AM »
The headlight Voltage drop can cause regulator problems on Guzzis but I don't think the Strada senses from the headlight circuit. Interested to hear about your fix though.


Sent from my shoe phone!
72 Eldorado
07 Griso 1100

Moto Guzzi - making electricians out of riders since 1921

Offline not-fishing

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 1015
  • Location: Folsom, Ca
Re: Overcharge, or OK?
« Reply #6 on: July 18, 2017, 09:25:56 AM »
My boy and I went though this with a 1980 V50.  I had him take off the battery connections and ground and dremel them bright and shiny.  This along with another direct jumper to positive (Patrick Hayes suggestion -Small Block Starter Relay Fix - http://www.guzzipower.com/SmallBlockRelay-PHayes.html) has made the little Goose starter really spin.

On bikes older than 10 years I always look at the connections.  and all my rides are older than 10 years

Mark
Griso 1100
Rosso Corsa Lemans
1/2 a V50 III (with my son)

Offline Chuck in Indiana

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 25210
Re: Overcharge, or OK?
« Reply #7 on: July 18, 2017, 11:17:47 AM »
Over charge on an AGM is not ok. Anything over 15V will make them into a very fine anchor in short order.  :smiley:
Chuck in (Elwood) Indiana/sometimes SoCal

02 Scura RC
87 AeroLario
79 G5
95 Skorpion tour
 
Sometimes it's easier to remember when you worked on something than where it is..

Offline 1Sourdough

  • Guzzi Hero
  • *****
  • Posts: 607
  • Location: North Iowa
Re: Overcharge, or OK?
« Reply #8 on: July 18, 2017, 02:36:46 PM »
You guys may be onto something, thanks.  Last year I was getting intermittent discharge (battery) light, and at 3,000 to 4,000 RPM the engine would cut out for a moment.  going over the connections and adding the ground wire seemed to have resolved that but you are pointing to causes which seem close enough to go over those points again.  I'll have a look when things cool down a little this evening.
1993 Strada 1000, 1996 R1100RT, 1999 V11 EV
                            -30-

Offline 1Sourdough

  • Guzzi Hero
  • *****
  • Posts: 607
  • Location: North Iowa
Re: Overcharge, or OK?
« Reply #9 on: July 18, 2017, 08:47:41 PM »
OK, per usual, I am bewildered but that goes with the sickness of owning a Moto Guzzi, eh?.  I released the two clips I have seen along the sides of the ignition switch, and removed the cable plug.  The blades on the bottom of the switch are clean and healthy looking copper.  Worked the plug on and off several times anyhow, and did the same for the Molex plug 10 inches or so along the cable. 

The ignition switch, less the plug, is five or more inches long, and I don't see how it may disassemble.  If there are continuing troubles I will try fiddling with it.  Did not do so tonight.

Have already performed the start relay upgrade, so did not redo that.

Found the two conductor plug coming off the regulator, pulled it apart enough to probe the pin: 11.7 volts with the ignition on, engine stopped.  Worked it on and off like the others.  Going on to the next suggestion I disconnected the headlamp. 

Started the engine, ran it to 3,000 RPM, 13.4 Volts.  Increased to 4,000, 13.7 Volts.  Both stable with even RPM.  At idle the discharge light came on but went off as soon as RPMs advanced above that.  (Sometimes it has come on at higher RPMs, sometimes it does not illuminate at idle.)

Is there a range of voltages which are acceptable on that regulator lead, or does it really, really, honestly and truly want to be at battery voltage?  If the former, I have no idea why the charge rate is at normal level now.

Fred
1993 Strada 1000, 1996 R1100RT, 1999 V11 EV
                            -30-

Offline Chuck in Indiana

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 25210
Re: Overcharge, or OK?
« Reply #10 on: July 19, 2017, 06:07:24 AM »
Quote
3,000 to 4,000 RPM the engine would cut out for a moment.

Ok, this is ignition. Power comes from the battery to the ignition switch to the kill switch to the "sidestand" relay to the ignition relay. Any one of these can cause this. If you haven't removed and squirted some DeOxit in the sidestand (farthest aft in the stack) or ignition (up by the fuses) relay bases, reinstalled the relays and wiggled them around.. I'd do that.
Chuck in (Elwood) Indiana/sometimes SoCal

02 Scura RC
87 AeroLario
79 G5
95 Skorpion tour
 
Sometimes it's easier to remember when you worked on something than where it is..

 

Flying Tiger Motorcycles
Moto Guzzi, Royal Enfield, Zero Electric Motorcycles
FlyingTigerMotorcycles.com
Advertise Here