Charging Question

[MtnMax/Magniac]

Just installed a volt meter on my '85 Max, and it shows 12v static and at idle, 13v at 2,000 rpm, then drops back to 12v at any higher rpm. Does that mean my r/r is kaput, or about to go? I thought it should show up to 14v at higher rpm's.

 

[maleko89]

Use the fault finding guide in the electrical section. It's a sticky.

 

[alorio1]

I would start with a fully charged battery, then start on the fault finding diagram. Check stator connections and clean Rectifier surface where it bolts to left foot peg. Bad grounds and connections are usually the culprit, most run a single ground wire from rectifier mounting screw to a alternate grounding source (screw by faux lid cover).

 

[Fastatv]

Just installed a volt meter on my '85 Max, and it shows 12v static and at idle, 13v at 2,000 rpm, then drops back to 12v at any higher rpm. Does that mean my r/r is kaput, or about to go? I thought it should show up to 14v at higher rpm's.

Mine does a similar thing but only on cold start up. After a few minutes, jumps up to 14V when rev'd. This may not be normal but mine always starts and I have never charged the battery.

 

[gamorg02]

Mine does a similar thing but only on cold start up. After a few minutes, jumps up to 14V when rev'd. This may not be normal but mine always starts and I have never charged the battery.

mine acts similarly. i never put a voltmeter on it but my shift light has one and just used that. not sure if it ever recovers. i'd be more concerned if it didn't always start up awesome!

 

[MtnMax/Magniac]

Muchas gracias, as they say down south. Or, further south, it might be muchas gracias Y'all! Put the charger on overnight, I'll check it again this afternoon.

 

[RaWarrior]

That also depends on where the voltmeter gets its power from. I have a Venture stator and a ZX-14 r/r and have a perfect 14.4 volts measured across the battery. At the headlight it's only about 13....losses due to the bike's generally shitty wiring harness, too-small wire gauges, chintzy crimps, and lossy switches.

But you certainly wouldn't be the first person to have a stator or r/r go kaput. Use a multimeter across the battery. If you have at least 13v, you might not be optimal but shouldn't have charge issues. Less than 13v I'd start investigating.

 

[daves86vmax]

not sure if this helps but i've had issues with my 86 dropping its voltage when the bike got hot to where the fan would kick on,when it kicked on the voltage pulled down to about 12.3 or so and it would stumble and want to die on me..i replaced the R/R,the stator with a venture stator,soldered the stator to the R/R,and the R/R to the main fuse and the main fuse to the harness,put on ngk boots and 8mm taylor wires over the past 2 years and pretty much cleaned every connection on the bike....it still lost voltage.what finally fixed it was the cop upgrade that i got thru Sean Morley,it now runs flawlessly..i noticed that when i pulled the plug wires out of the stock coils that one looked like it melted from possibly arcing between it and the spike inside the coil that it was supposed to seat itself on.i think the 8mm wire was too big to fit in far enough to make a good contact or perhaps the stock coils were just bad but i think alot had to do with the 8mm wire size even though they were sold on ebay as vmax wires.i did the flow chart check and everything would check perfect until the fan would kick on so i'm pretty sure the coils/coil contact with the wires were the culprit.i wish i wouldve done this mod a couple years ago and saved myself alot of heartache.the COPs' made me a believer

 

[MtnMax/Magniac]

Well, it looks like I just may have voltage drop from the wiring system to the voltmeter. When I use my multimeter and read at the battery, all is fine, high 14's at higher rpm's, but the aftermarket voltmeter never shows more than 13, wired to the headlight circuit at the fuse box. Don't think I'll spend any more time worrying about it.

 

[gamorg02]

interesting. i did a couple checks with mine, even warm yesterday. after sitting for 24 hours i was at 12.6v, at idle 13.4v and then at 2500 rpms, 13.2 volts..

sounds like its not all that uncommon either:

http://www.hondashadow.net/forum/72-technical-discussion/92322-charging-system-question.html

http://hondashadowacetourer.yuku.com/topic/12334/Upgraded-MOSFET-Regulator-Rectifier?page=1

http://www.hondashadow.net/forum/72-technical-discussion/99650-low-rev-voltage.html

http://www.gixxer.com/forums/archive/index.php/t-289338.html