wifes honda shadow 1100 problem...ideas please

[painterman67]

Ok heres my problem,

For 2 years straight now this bike has puked a battery. First was an original honda t type battery and now its a uasa that was installed new in feb. Went to crank the bike 2 days ago and it was dead. Checked the water and refilled with distileed water, jumped the bike and let it idle for close to an hr. BIked cranked back up after I cut it off so figured all is well. Today tried again same thing except water level was good. so put on the trickle charger thinking it just didnt get enough charge as it was showing 11.7 volts after 2 days setting static at 22 degress in the am. Charged for a few hrs and bike cranked wright up with full power. This is the same thing that happend on the first battery too.

 

Heres where i get confused. I put the multimeter on the battery at idle and its charging at 13.4 volts. Brought up the revs( no tach so just brought it up) and ay first the meter went to 20.06 volts and then dropped to 12.6 volts. Ilet it idle again and meter went back up to 13.4 volts. I then did an unscientific test and noticed every time I rev the bike and set the thumb lock to hold it the head light gets a little dimmer. Volt meter also drop back to 12 or so volts every time. Did this multiple times and never seen and thing over 13.4 volts and thats always at idle. I checked the meter on my 91 vr and it showed just over 12 at idle and 14.1 at 3000 rpm so Im thinking meter is good. Round about the same numbers when it was checked on the e-250.

 

So with all this Im thinking either a bad stator or voltage regulater. Any ideas.

 

Help please as this is her bike and Id really like to get it wright for her. She will ride mine but shes scared of the weight . She has a hard time bringing it up to center and then her toes just barely touch.

 

Any ideas are apreciated.

 

Tahnks in advance

 

David

[bkuhr]

Heres where i get confused. I put the multimeter on the battery at idle and its charging at 13.4 volts. Brought up the revs( no tach so just brought it up) and ay first the meter went to 20.06 volts and then dropped to 12.6 volts.

 

Think that this might be the clue. I would suggest to CHECK, DISASSEMBLE, AND CLEAN ALL the grounds. (Also get the AC phase wire connections). I am suspecting due to this volt spike, that a corroded ground is acting like a high resistance open, unloading the regulator for an instant-causing the spike, until the spiked voltage is high enough to 'burn' thru the corrosion, completing the regulator circuit. Also the high resistance -corosion, remaining in the circuit causes the less than optimal normal voltage (13.4 vs 14.1)

2 years of these spikes could also have damaged to regulator, but would not even think about replacement until grounds are repaired, and no more spikes. The 13.4v is close enough that maybe the regulator is ok, and a clean system will operate at specs.

 

All this assumes your Honda uses AC generator. I had a Honda CB350 used brush type DC generator. Same cleaning, connections should still help.

[MiCarl]

Interesting you bring that up.

 

I had a customer brought me his 1100 shadow saying it wasn't charging, he'd checked it with a volt meter and voltage was lower than before he started it.

 

I charged the battery and checked the voltage - 12.6. Started the bike up and the voltage jumped to 13.4 - not bad for idle. Thought the guy was nuts.

 

I revved a bit to see if it'd go to 14 or so and as soon as I got it off idle it dropped below 12. Back at idle 13.4.

 

Turned out to be the regulator/rectifier.

 

Interesting thing is the new regulator would climb to 14.2V then drop back to around 13.6 as it was revved higher. More recently I saw similar characteristics with a friend's Roadstar with both his used and a factory new regulator/rectifier. Apparently some of them show this kind of characteristic.

 

Bottom line is you need to check out the stator and all the connectors first. But don't be surprised if you end up with a new regulator/rectifier.

[Condor]

I had pretty much the same problem with my RSV in Cody this summer. Turned out to be the rectifier. I knew I had problems before I left as I was getting 17vdc when the bike was running. I didn't have time to mess with it before leaving so tossed a new rectifier in the trailer and took off. Apparently I was running on battery power only. 17 volts..no amps. The battery died 80 miles from Cody. I'd run about 1200 miles and 2.5 days on battery power only. The DEKA was dead.. dead..dead... 8.9vdc on the meter. To make a long story short, replaced the rectifier and problem solved...

[CaptainJoe]

Make sure you sure after you clean your grounds, connections and battery posts to use a good anti-oxidant. Available at lowes for $5 in the electrical section...

 

I also use this stuff on bolt threads and they never oxidize/RUST.

 

Stators can easily be tested with a multi tester. Look up in specs and if it's not within a certain range it's bad.

 

Process of Elimination...

Are the grounds and connections clean and anti-oxidized, and, "tested good" with a multi meter. Make sure there aren't any open continuity problems.

Do Stators "test good", Resistance check...

Battery "new" or did you take it someplace to get it load test (advance auto)

Regulator/rectifier? Don't know if it's possible to check these but if your reving and its only 12 volts I'd be leary...

Edited November 22, 2011 by CaptainJoe

[RedRider]

http://www.hondashadow.net/forum/

 

Been working on my brother's Shadow and this forum has been helpful. Post up and see what they say.

 

Sounds like a rectifier to me.

 

RR

[PBJ]

Same advice from me . Hondas are known to have rectifiers that will do that. Mine on my 84 V65 Sabre will boil the water out of a cell if i don't keep an eye on it, all advice here is good. Clean the connectors and check again or just replace it and see where it stands but those things should solve the problem. good luck.

[painterman67]

cleaned all the grounds today....no more spiking volts for now.............still have a drop in voltage when I crank up the revs .......I have no idea how to do the checks so Im thinking a trip to a friend or a dealor is in the future......for now its holding a steady charge....I put the battery on charge last night and it held 12.7 volts 6 hrs after the charger was removed.......bike cranked wright up when I put it abck in so Im thinking rectifier or stator but Im out of my league now. I can see the rectifier but can find the conections ....and at $109 plus change itll have to wait a bit

 

 

DAvid