Faulty Alternator or Regulator

brian gains

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So continuing from a previous query. Having replaced the battery as per Martyn's suggestion, with a lithium battery, they are so incredibly light I thought I had been sent a display dummy, issues still persist.
The volt meter does not register a charge with the lights on when running. I have replaced ludicrous high wattage headlamp bulb with s 65/60 and even removed one of the twin tail light bulbs, Where do I go next.
The Kubota pancake two wire alternator obviously works, are there different output models available and a lower output model could have been fitted or, can the stand alone solid state regulator fail to give ample charge?. Woold seem to me if it is solid state it either works or it doesn't.
Wiring is so basic I can't see where power is 'leaking'. This is not an issue of the battery running flat while parked up.
 

Bill Thomas

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What does it do without the H/light on ?.
I thought the Kubota came from a tractor ?.
If you say the Kubota works, The only thing left is the regulator on the fact it's wired P/earth ?.
I am only guessing, I am rubbish at electrics, But I am interested as I have a Mcdouglator.
 

BigEd

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Why is it wired positive earth? Likely the only thing that is polarity critical is the rectifier/regulator. If the alternator is actually putting out any AC to the rectifier you should be able to measure at the output leads with a multi-meter and see if there is any voltage output and also see which of the leads is positive or negative. The positive lead should go to the positive side of the circuit and in your case the battery should be connected to the same side.
If you are getting voltage at the rectifier output leads that is not proof of the amount of current. (Amps) You could put a bulb across the leads to get some idea of output.
 

brian gains

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no idea why the machine was wired + earth. With a fresh battery and lights on there was indicated a low but + charge on the headlamp voltmeter, after about 20 mins riding I noticed there was no indicated charge so the lights were turned off. Within minutes the voltmeter indicated max charge on the voltmeter. There is nothing remarkable about the lighting system and I just keep returning to the two dual output coils, could they be placing an exceptionally high load?.
Enough of these Kubota alternators seem to be used for alternativw applications so in reasonable conditions they must be up to the job.
I acknowledge that LEDS would place less load on the system but at this time that would be a sticking plaster for an on going issue.
Next step I guess is to disconnect and introduce each bulb to see what the effect is.
There are no blown fuses or signs of melted wires, could the use of inappropriate heavy gauge wire in the loom cause an issue?. there certainly is a heck of a lot of wiring for such a basic system, but then with my ignorance of wiring I work to the KISS principle when I wire m/c's.
 

Bill Thomas

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I wonder what the gearing of the alternator to engine is, Could it be as simple as that ?.
I bet the alternator was done a long time ago, Maybe before these big Headlights where the fashion ?.
Could you do say 50 miles without the headlight on, With say a big pilot light, Or rig up a daytime running light, Say 30 watt ?.
That might prove something ?.
 

Bill Cannon

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If you have a multimeter turn it to AC setting with a range up to at least 50V. Check the output directly from the alternator. At reasonable revs, say 1500, you should get in the region of 35V. If so your alternator is almost certainly OK.
If I were in your position I would rewire the bike to negative earth. As mentioned the regulator is an electronic device and is highly likely to be polarity sensitive. Unless you have electronic ignition the only change will be the wiring of the ammeter.

Good luck
Bill
 

Roslyn

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I know this is not Vincent stuff but I did put a solid state voltage regulator on my triumph wired it as instructions and double checked every thing and it discharged the battery right out down to two volts it recovered after being recharged I am back to a using a old trusty MC2 now
 

Bill Thomas

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Just looked up McDougleator 1,1/2, times engine speed,
Over to you Brian ?.
In thevincent.com Our Bruce and friend , Said the LED headlight uses a lot ??, But that was 2010 !!.
 
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