Well that didn't last long!

[Superjet]

Well as mentionned in a couple threads about stock charging systems I have kept it on my 1983 with stock ignition. Have 236 kms since all in working order charging 14.7v at over 2000rpm. Here is what I have done.

So called new rotor (4.7 ohms)
New windy nation rectifier
New Napa VR38 Chrysler regulator
Stock stator check out good
New Showai LFX battery fully charged.
New brushes.
New wiring.

Last night started off with charging at 14.7v running normally since first got going with all parts together. 30 mins in the ride look down at my lcd volt meter and showing 12.8v. Turned lights off and headed home. Got home let cooled down and took brushes out. Very little brush dust and length looked like new. Slap test still ok but not as good as first tested with all initially. Tested resistance on the rotor 1 ohm....ohhh man that sucks. Not much to say about a "new rotor". Guess I am on the hunt for another one or get rewound. I do still have the old stock one. I am in NB Canada so not sure what costs would be to have rewound. Gonna contact vender for a refund on the rotor....man bummed out for sure. Finally got it all running great and now this. Any comments would help bring my spirits up! Thanks guys. J-C

 

[jussumguy]

If it makes you feel any better Ive got the same bike, pretty much same modifications and dealing with the same issue. My rotors go for about 700 miles though. ill probably put one more rotor in it before I try the ninja 250 charging system and pamco.

 

[gggGary]

14.7 is pretty high. are you SURE you guys have a functioning regulator? Full power full time will smoke any rotor in short order.

 

[Superjet]

Well looked at the manual and shows 14.5v +/- 0.5v should it be different ggggary? I have a fiat regulator but i guess i must of fried my rotor by the sounds of it.

 

[gggGary]

I'm sure there are crap repo rotors out there. I have had a cheapie rotor on resto for several thousand miles now.. (stock mechanical regulator, LOL)

 

[Superjet]

I do have led headlight and taillight but have regular filament turn signals. With signals on voltage drops down to 14.4 or so. What is your resto running for voltage?

 

[gggGary]

Well madness which has the stock type rotor and an unusual hot side of the brushes electronic rec\reg was showing 13.7 pretty much all the time last night. but the leads are both up near the headlight so may be reading a bit lower than if they were on the battery. I think resto is showing up into the 14's

 

[gggGary]

So I went and checked resto also shows mid 13's at all engine speeds..
I put a separate voltmeter directly to the battery terminals on madness. got about .5 volt higher reading directly to battery slightly more at idle as the headlight and other loads without much alternator help, dragged down voltage at the headlight. Picture is engine not running headlight off, I only have so many hands

 

[Superjet]

Well that gives me a start. My lcd voltage meter is directly wired in after my switch from the battery. Sounds I should be seeing mid 13's. With headlight off and bike not running I had 13.3 or so volts when all was working. I will deal with rotor exchange and switch my regulator to the fiat one I got on ebay. I will update to see what results will be. Thanks gggGary for the info. Your help and knowledge is great.

 

[5twins]

The only LED I have is my tail light, and the only reason I did that was to reduce the draw on the battery for electric starting because my tail light comes on with the key (I have plans to "fix" that, lol). The draw is so small it triggered the brake failure warning lamp on the dash, lol. I guess the light checker thought it was burned out, so I just took the bulb out of the warning light. But that worked out fine because then I used that location for my voltmeter, and the empty bulb socket to power it .....

 

[gggGary]

Hey 5t how did you clean up the back of that red lens so the LED is clear to see??

 

[Superjet]

Guys I dont have many lights on my bike. I have a small round led taillight and the headlight is a daymaker led for a sportster. I have a backlight for the cheapo speedo and cheap filament signals. Not much for loads on my bike. Oh and a diode for neutral. I took another look at the original rotor I took out. I cleaned up the rings and it measured 3.7 ohms. For fun I may try it to see what reading i am getting with the vr 38 regulator from napa. Then i will switch out and put the fiat unit in. Just wondering if readings will be up around 14v.

 

[Superjet]

5twins I like the way you wired up the lcd display with the socket. No cutting of original wiring....Nice!

 

[5twins]

I have found slightly different set points on regulators from different manufacturers, so yes, that's worth a try.

Gary, I didn't do any "modding" to the red lens, just wiped it clean. I thought of trying, trying to grind down some of those tits around the perimeter, but it was just too hard to get to. It worked out well enough. Not visible in direct sunlight in the middle of the afternoon, but neither are any of the factory lights under those conditions. A little shade, even just from your hand, allows you to see it. I got some new units with yellow lit numbers instead of the red. I'm thinking/hoping maybe they might show through better. But for a stand-alone mounting, not having to show through a dash window, I do like the red numbers.

 

[Paul Sutton]

As pointed out above the stock specification for the regulator is 14.5+/-0.5V. I have used two different regulators to date in my DIY rectifier/regulator. The first was spec'd at 14.2Volt for an ACR 14/15/16 alternator and it always stayed between 14.1V and 14.3V. The second is the Atype Fiat regulator and it is spec'd at 14.5V. In use it controls at 14.6V. On my bike the voltage at the ignition switch brown wire is the same as that across the battery.

The 14.2V ACR regulator shows 14.2V from approximately 1800rpm and up. The Fiat 14.5V requires 2500 - 3000rpm to stabilize at 14.6V and below 2500rpm the voltage drops of to 11.6V at a 1200rpm idle. When riding the voltages goes up and down with the rpms for the Fiat whereas the 14.2V ACR regulator was much more stable.

Edit 24/05/18: The voltage/rpm characteristics of both regulator are similar. Found this out today after repairing the dropped phase. The Fiat gives 14.2V at a similar rpm to the ACR, it just takes a lot more rpms to get up to 14.6V.

If I understand regulators correctly then if the specification is 14.5V then at higher rpm the voltage should stay very close to 14.5V irrespective of how charged the battery is. The current drawn by the battery drops off as the level of charge increases purely as a result of the battery chemistry, but the regulator should remain close to its specification voltage. I do not believe that the voltage on the system will drop off as the battery approaches full charge because the regulator is hard-wired to control voltage. I would love to know the rotor current draw when the voltage shows 14.7V and I would not be too surprised to see a low value like 1 - 2 Amps.

Coincidentally tonight while riding I lost connection to one of the phases. In the process of diagnosing I measured the rotor current with ignition on and engine off - 1.25A. Does this seem reasonable???

Note: I think the lost phase is either due to a poor connection in that connector between the carbs or a cracked wire from this connector down to the stator. It is an intermittent fault I have been chasing for the last 4 - 6 months.

Edit 25/5/18: Just been ready the specifications and the XS G model and later have a regulator specification of 14.5 +/- 0.3 V. I guess that in going to the electronic regulator the spec tightened up from the original +/- 0.5 V.

 

[Superjet]

Paul I cannot measure amps at 14.7 any longer as the resistance of my rotor have been reduced. The way I have it wired is as such: battery to switch and on same side red from rectifier. On side of switch lcd and blade fuse panel to all other devices. Lcd voltage meter is before any load on the bike. Would that matter at all? In my mind it would be on any part of the brown power wire on a stock setup.

 

[Jim]

Coincidentally tonight while riding I lost connection to one of the phases. In the process of diagnosing I measured the rotor current with ignition on and engine off - 1.25A. Does this seem reasonable???

Ohms law shows about two and a half amps for 12V and 5 ohms (batt. and rotor)... does seem a bit low.

 

[Signal]

Jim I don't think Ohms law is directly applicable as there will be reactance adding to the total impedance in the circuit limiting the rotor current.
I have never read the charging guide, but it may already be established what the standing current draw of a healthy rotor is.

 

[Jim]

Jim I don't think Ohms law is directly applicable as there will be reactance adding to the total impedance

Right you are. Damned inductive reactance got me again......

 

[jussumguy]

I'm using a motor craft version of the Chrysler regulator. I get 14-14.5 volts going down the road. I have an analog gauge rather than a digital display.
(With the motor at 3000- 6000rpm and headlight on and 2 led bulb tail light) I check my rotor for ohms and get zero. Must have broken a wire inside. Tried calling custom rewind and they don't answer. Michael Morse sells them for $175 and he's just a couple hours away, I might do that.
They cost more because they're better...right?