As you rev the bike, what's the highest the volts get to?
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Another Fouled Plug Thread
- Thread starter DavidIsaak
- Start date
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- fouled plugs plugs spark plugs
DavidIsaak
XS650 Enthusiast
OK I just did it again with the help of my girlfriend and at 2500 rpm I was reading around 13.4v as mentioned and climbs up to 13.5 -13.6v at 3500 rpm.
It seems the volts climb as she was revving the bike. I thought I caught the highest of about 13.6v around 3500 rpm. Did not rev higher than that.
The rectifier/regulator unit is original, but have acquired the parts to build a new unit (winter project). In your opinion, Jim, is there cause for concern or anything I should be immediately worried about right now?
I would think there are several considerations to be taken into account on the difference between the US BS34 set up compared to the Non US BS34 set ups
Shouldn't the Non US Needle jet 336-YO, (main Nozzle with the 4 extra air holes), also be taken into account when deciding where the clip sits on the 5IX11 needle. Also the taper on the 5IX11 Jet needle is different.
Haven't really looked but a question i ask is, does the 366-YO also have a different taper than the US Y-O Needle Jet.......??
Not a good needle, but i took this out of an Oceania BS34 Carb with a 130 air jet and 135 Main.......joined it to one of your pics 5T
Worked on many 100s of charging systems on cars. We always hooked a voltmeter to the battery and also hooked an ammeter series in between the alternator/generator and the system. Voltage only tells half the story. If I was working on a car with a 60 amp alternator for example and at 2000 engine RPMs the voltmeter read 13.5 and the ammeter read 60 amps coming out of the alternator, the alternator was not the problem. Either the battery was sucking up the amps trying to get charged up or it was bad. It is very possible to have low voltage at the battery and nothing wrong with the charging system.
Too expound a little further it is very possible to have a perfectly good alternator and regulator and have low voltage at the battery. As has been mentioned here many time volt drop through switches and connections can fool the regulator into under charging the battery. Many times on cars had to check the system voltage at the regulator and compare it to the battery voltage. It is always best to check a system with a fully charged and good battery.
Sorry bout that Jim! missed the rotor had been replaced, was thinking he still had the 2 ohm rotor in there. Good point GLJ need to make sure there isn't an unexpected heavy load. Or could be a voltage regulator with a low set point. Short the brush to ground (only do this for a short time, several seconds, enough time to rev the motor and see what the voltage does),
of note; "Lithium Ion Battery that is in good working condition"
of note; "Lithium Ion Battery that is in good working condition"
That's a hard one to call. I'd hate to opine it's ok and have you burn up the rotor you just paid good money for...
Mines an 80SG. I just replaced the reg/rec on it 'cause it was gettin' flaky. Yours is only a year newer....
Did you pick up a type 'A' regulator?
DavidIsaak
XS650 Enthusiast
I bought the Fiat regulator and windynation rectifier. Link for what I am following below:
http://www.xs650.com/threads/creating-a-new-regulator-rectifier-from-scratch-1980-and-up.52990/
So if I tested my reg/rectifier (page 1) and it is showing OK, what's next? Is it worth building out this new rec/reg and installing ASAP to see if it will help charge?
You checked the rectifier side of it. Unless you have a variable DC power supply, you can't test the regulator part. So it's an unknown.
There's different Fiat regs. Is it the VR794?
DavidIsaak
XS650 Enthusiast
Reading further in my Haynes manual again, it does sound like the regulator could be the culprit here if I am not achieving 14.2 to 14.8 volts at 2000 rpm. I know my connections are tight because I have cleaned the connectors and applied dielectric grease. I have also checked for frayed wires, etc.
Will check everything over in the morning. Good thing rain is in for the forecast. Sounds like it will be a good time to build the new rectifier/regulator unit.
Will check everything over in the morning. Good thing rain is in for the forecast. Sounds like it will be a good time to build the new rectifier/regulator unit.
DavidIsaak
XS650 Enthusiast
It is this regulator:
https://www.ebay.ca/itm/192892968582
OG part number 4475112 which cross references with VR794 from what I can tell in this ebay listing:
https://www.ebay.ca/itm/VR794-1979-...ash=item1c6f7114ab:g:1xcAAOSwv6FbrNB8&vxp=mtr
Did you do as Gary said above? Rev to about 2500-3000 rpm and momentarily ground the green wire at the brush. If it jumps to 14-15V, it's the reg.
If it crosses to the 794, it's the correct one. Green wire to green... red to brown.
DavidIsaak
XS650 Enthusiast
I did as mentioned and shorted the green wire at the brush to the battery ground and witnessed no jumping in voltage. I only saw about 0.5 V on my voltmeter while revving. Is that correct? Or did I not follow your directions correctly?
I checked the voltage at the battery after doing all this and my battery was reading 13.16 volts.
No. It should have stayed the same or increased. Dropping to 0.5V makes no sense. Let's do this to get a baseline here. Give us these readings:
1. Battery voltage (B.V. at the battery) with the key off.
2. B.V. with the key on (not running).
3. B.V. with the bike at idle.
4. B.V. at 3000rpm.
Just for grins... do this slap test to make sure the rotor is getting energized.
DavidIsaak
XS650 Enthusiast
Are you saying the voltage at the battery dropped to zero point nine volts? The green wire at the brush goes back to the regulator. The regulator grounds that wire to energize the rotor. All you are doing by grounding it is bypassing the reg. I don't see how a battery drop to .9V is even possible.
1, 2 and 3 are normal. 4 sez it's charging... if a little low.
DavidIsaak
XS650 Enthusiast
I don't know what I am saying except what I already said. I don't understand it either, so I am assuming I am doing something incorrect in testing. I keep reading and reading and troubleshooting to no avail.
If I am not damaging anything by riding I will continue to tinker away and ride my bike as is.
Well, you're not overcharging.... which is a good thing. I don't think you'll hurt anything but don't hold me to that if sumpin does break.
Keep checking the batt voltage to make sure your batt isn't discharging to the point you'll get stranded.
Any chance of getting a closeup pic of the brush holder as it sits right now?
