Honda VFR400 NC24 electrical problem...

[Kwaka-Kid]

it starts.. about 1 month ago my lights were going bright and dull... rode for 2 weeks like that, and checked battery, it had boiled DRY. put another battery in, rode for a week, checked it and it was half empty. i decide my reg/rec is stuffed and i put one from my perfect NC35 on.. splice wires and put it in, noticing that in one of the yellow wires connector block (where it carrys onto the stator or whatever) it was black and look as if it had exploded.. possibly not touching at all, but i scraped it out and sprayed WD40 in and plugged it back together (just hoping that the yellow wire was connected thru it, not checking) and i rode for 3 hours with headlamp on up north.. did 1 hours worth of riding around up there where once the bike went flat.. i push started it and thrashed it for 30mins with headlamp off... and the battery seemed charged (tried once to start, yup).. started it the next morning to get home.. fine, decided to be careful and turn off headlamp... got 30mins south and it come to a halt... no power.. push started it and away i went.. for 5 mins.. then same problem.. put brake on and the power of hte brakelight killed it... waited 10mins.. push started.. yay, heaps of revs for about 2-3mins riding along and boom.. ran out of power again.. i gave up as it was getting worse and worse and i brought home in my van.. now im left wondering what is wrong? my reg/rec looks fine + its out of my race NC35 that had only done 19,000km... oh and this NC24 has done 28,000km now... please can someone help? have i blown my stator? what would happen if that yellow wire (1 of the 3) wasnt touching? why did it run so long with headlamp on?... cheers guys! all advice is much appreciated.

[Andrew]

Ok this is what I think has happened.

Your battery has been boiling dry right? This is because it has been charging at too higher voltage. When your battery is charging at too higher voltage (above 13.5 VDC) the plates in your battery begin to start flaking. The flaking bits of metal from the plates line the bottom of your battery. This means that the internal reistance of the battery becomes significantly less.

As a result from a higher charging voltage and lower internal reistance of your battery you will have proportinally higher charging currents.

This will mean that that your alternator will be putting out higher charging currents than it is designed to. Since current is directly proportional to temperature the temperature of your windings will be getting a lot hotter beause it is putting out a higher charging current.

So what would cause this? Your regulator rectifier unit will have stuffed. Now usually you should be able to replace this unit and your stator windings with any luck should be ok. What I think has happened in this case however, is that unfortunatly your bike has dropped a stator winding.

your altnernator will put out 65V AC (RMS) and it will be 3 phase. What you need to do is get a multimeter and check the continuity between all the phases (stator windings). If all three windings check out ok, next start the bike up and make sure that you're getting the 65V AC from each phase with respect to ground.

If you don't get continuity between the windings or an incorrect output voltage, I more or less think that the stator windings of your alternator have burn't out. If this is the case you will have to get your altnernator re-wound lots of $$ and can take some time to get done. If you need to use the bike in the mean time, but the battery on charge overnight with an independant charger. Make sure that your regulator rectifier unit is unplugged from the circuit. use the battery to start the bike, but don't use indicators, and don't use head lights. This should get you around if you have to, but use the GS if you can.

Hope this bullshit makes some sense, if not just go to a mechanic and get them to just quickly tell you if the windings in your alternator have burnt out.

[Kwaka-Kid]

makes lots of sense andrew, and almost exactly what dads mate told me, but he said measure hte AC voltage between any and all 2 of the yellow wires coming out of hte stator? not to ground.. then check resistance to ground, which should be none. and yeah he said anywhere between 50V AC and 70V AC should be coming out of my stator. and yes i know its 3 phase hence hte 3 yellow wires right? yay! but yep will do this after today.. going to work on the GS.. and i have a race bike which is about to loose its charging system.. with luck will my NC35 stuff fit into my NC24??? :S

[Kwaka-Kid]

Results = Each yellow from Stator to Ground = 1ohm ind. good... each yellow running to another (the 3 dif combinations) 23V AC @ 1,800rpm. 59V AC @ 5,500rpm. Checked battery... BOILED DRY in approx 4 hours of 100kmph riding... checked current thru battery.. flex revving around 5-6000rpm, 14.8V up to 14.9 but not quite 15V... hmmm... new reg/rec? i can get a brand new VF750/VF1000 mid 80's one @ a good price...im told by my mate these are the BEST honda ever made and have a sensor wire that i wire anywhere after ignition to a positive feed. e.g rear brake light... and that changes the reg/rec etc and its a heavy duty one, reckons it will outlive the bike easy... what do you all think?

[Redstar]

Results = Each yellow from Stator to Ground = 1ohm ind. good... each yellow running to another (the 3 dif combinations) 23V AC @ 1,800rpm. 59V AC @ 5,500rpm. Checked battery... BOILED DRY in approx 4 hours of 100kmph riding... checked current thru battery.. flex revving around 5-6000rpm, 14.8V up to 14.9 but not quite 15V... hmmm... new reg/rec? i can get a brand new VF750/VF1000 mid 80's one @ a good price...im told by my mate these are the BEST honda ever made and have a sensor wire that i wire anywhere after ignition to a positive feed. e.g rear brake light... and that changes the reg/rec etc and its a heavy duty one, reckons it will outlive the bike easy... what do you all think?

what you said implies the inputs from the stator are good? but the overall output voltage is too high? so that would indicate the regulated voltage is excessive? what about putting a zenner diode in the battery live line to shed the excess voltage (whats the F##k is that) a zenner diode dumps excess voltage to ground? I can bullshit ah! (RMS=Root mean squared) and = 0.701 of peak voltage bet u didnt know that then! or you could get your wad out and buy a new reg/rect.Honestly I only know enough to be danderous ignor me

[Kwaka-Kid]

hmm thanks for that input dude, im getting reg/rec now anyways, but its an idea alright... a bit more then 92% and 2nd highest in roskill grammar back in 4th or 5h form electronics is needed i think...