NC30 sulphur smell and hot battery

[JZH]

Your charging system is slowly burning up...

You have already had a big clue--the sulphur smell has only one cause, and that is a battery being hit with 17+ volts, overheating and the safety valve (that's why it is technically called a "valve-regulated lead-acid" battery of absorbed glass matt construction) allowing the excess pressure to be vented to the atmosphere. It could be worse--I once had a battery do what you've described as well as spit acid all over the rear subframe...

Please note that reg/recs do fail intermittently, so may test okay one day, and go crazy the next. But the boiling battery is an unambiguous sign of a damaged reg/rec, and batteries subject to such abuse are most likely permanently damaged, so you've already definitely got to replace a reg/rec and a battery. Weak points in your wiring harness have also shown signs of damage, so will have to be fixed/replaced. That connector may be the only damaged connector, but I would definitely check all wiring and connectors in the bike's charging system to be sure.

That connector and its terminals are avaialble separately, in case the existing ones cannot be salvaged.

Ciao,

[Sunnyday]

When you fix this solder all the joints its not as if you will need to take the regulator on & off anytime soon - that way you get less resistance - done mine 10 years ago and all is still good.

[speedy231278]

Classic sign of road crap getting into the connector, corroding one of the wires, and then the resistance starts going up, causing the burn to the connector, and slowly roasting the reg/rec that runs bloody hot anyway. The stator may well be fine, but measure the output just to be sure. Also, check the plug for it where it plugs into the loom. I'm not sure where it lives on the NC30, but I guess it's in roughly the same place as the NC35, and will be located on the right fairing bracket. I found mine to be corroded to buggery a couple of years ago, adding the problems caused by the corrosion at the other end. I cut the wires back until I found clean copper - and that was quite a way back!

you can get replica reg/rec plug kits on eBay from a seller called Nadia Autoparts. Overseas, but quick delivery. It's not absolutely stunning, but it's pretty decent for the money. When wiring the bits up, crimp the first part of the connector onto the wire, then solder the wire in. Wait for it to cool completely, then crimp the second part of the connector onto the insulation. If you crimp both bits and then solder the wire in, the insulation will melt around the crimp and it won't do it's job properly, and the wire will be able to move about. Over time, it might break. I also run a length of heatshrink tube over the crimped part to help reinforce it and keep a bit of crap out. It's also worth getting some decent insulation tap and wrapping it around the base of the connector and onto the loom so that the connector is sealed from the elements.

I did the above on mine, and it helped no end with the output, as did taking the output directly to the battery using heavier gauge wire (you need to put a fuse on the positive side if you do this). Now, it seems I have another dodgy reg/rec, so I've been to the shop of RO for one of his trick MOSFET units and a new stator for belt and braces. I'd love to meet the person who designed the charging system on the NCs, and shake him warmly by the throat... lol

[Luke86]

thanks for the advice chaps, very handy and will take this into account when replacing the reg/rec, and be sure to do the spades properly. Getting the bike back tonight all being well so will look at the alternator.

Speedy - i did see that MOSFET and was tempted, but it's cash i don't have right now, so will be sticking with the shunt, albeit set up properly. Hopefully i'll get the bike back tonight, and checking the alternator is first on my list. You're right that the alternator connector is on the right side, pretty much the same place so i'll be checking continuity there. If you do find the person who made it, make sure it's a firm two handed shake yeah

[Luke86]

Quick update.

Got the bike back today, checked the alternator connector, pin-to-pin, and earthing, and no continuity across any of them which is at least a good sign, and infinite resistance when earth checking. Haven't had a chance to check the stator coils, but will do that when replacing the reg/rec and battery, will also be doing a good check on the wiring looms and earths to make sure there are no other gremlins lurking.

[Neosophist]

that smell might just be the burning of the wires. that burned wire is caused by corrosion.. every couple of months clean up the connectors and spray wd-40 in there to keep out moisture.. as above incresed corrosion = more reistance and more heat which makes melt.

drop in voltage you noticed could have been due to loosing one of the phases due to the melted connection.

Key to long life is to ensure good connections and change the battery every couple of years.. old batteries dont charge well and it over-stresses the reg/rec as its not very large and easy to kill.

if you stay on top of your battery maintinance (always keep the battery fully charged and change it before its past its best) then even the stock reg/rec is fine..

due to it not having much lea-way in being able to take neglect it gets a bad rep. An aftermarket one like an r6 is much larger and will take more abuse.