Hey guys,

I think my reg/rec may well have had it. I've been through the whole charging system with a multimeter and I'm almost convinced that's the problem. I've been looking to remake the bit of loom going from the generator connector up to the reg/rec connector and replace the reg/rec with an R6 item. I've seen these on eBay:

http://www.ebay.co.uk/itm/New-Yamaha-YZ ... 2505032718

and they're half the price of a genuine Yamaha one. Seems too good to be true. Has anybody had any experience with them?

Looks like expensive rubbish to me, you get what you pay for...

Try and find a used 1999-2005 R6 reg, it should be cheaper than the junk above.

Just so that we NC30 owners do not spend money unnecessarily, what leads you to believe the rect/reg is at fault?

Well, since you asked - I don't. I'm more of the opinion the genny's had it. After my bike dying at a set of traffic lights for the umpteenth time last Sunday, I bump started it (something I'm quite adept at now) and managed to nurse it back to my friend's house where we set about it with a multimeter.

There was a mass of electrical tape surrounding the part of the loom that runs alongside the subframe up to the bottom of the reg/rec, but no discernable connector. I think the reg/rec is from an NC21 as the connector doesn't plug directly into the bottom of it, but rather there's a 15cm length of cables running from the bottom to where the connector should be. Having unwrapped all the electrical tape, the yellow wires were connected with one of those crappy white plastic screw terminal blocks you get in B&Q, and the green and brown with green-corroded spade connectors. Without having any suitable replacements, we decided the best thing to do would be to chop out that piece of the loom and just solder the wires together. Having done this we then did the usual checks.

The three yellow wires coming from the genny all measure under 1 ohm between each pair, and open circuit between each one and the negative terminal on the battery. The thing that worried me was 2 of the wires read 12VAC and one read only about 0.2VAC. The battery read 12.5V across the terminals, and 13.5-14V when revved to 5k. This makes me think it isn't the reg/rec - surely it wouldn't cap the voltage if it was knackered?

I'm confused to say the least, but my mate is rarely wrong about bikes and convinced me to start with the reg/rec. I'm still weighing up my options, and haven't checked the condition of the connector down by the generator yet. Also, I've yet to check the earth point down there either. It took us so long to rectify the first connector issue that we ran out of daylight and decided to call it a day.

Any thoughts?

Check the output of the genny in AC volts - across each phase

Sounds like your genny is fecked

CMSMJ1 wrote:Check the output of the genny in AC volts - across each phase

Sounds like your genny is fecked

measure twice cut once

I was measuring the voltage in AC first time round. What do you mean across each phase? From each yellow wire to earth?

Did you measure the alternator output with the rect/reg connected, if so your readings will be misleading because of how the rect/re works. Your resistance readings indicator you have three phases. How good is the battery, if on its last legs it may not be capable of supporting the electrical load at idle, when the alternator output is low and is the reason the bike stalls and then cannot run the starter. 13-14 volts at 5000 rpm is good enough to charge the battery and should have given you a fully charged battery by the time you got the bike home. What battery voltage do you get at idle after a few minutes running at 4000-5000 rpm, if the voltage drops dramatically to 12 or lower at idle I would suspect a dud battery.

go here

http://www.electrosport.com/technical-r ... ding-guide

download the pdf and see whats happening

magg wrote:Did you measure the alternator output with the rect/reg connected, if so your readings will be misleading because of how the rect/re works. Your resistance readings indicator you have three phases. How good is the battery, if on its last legs it may not be capable of supporting the electrical load at idle, when the alternator output is low and is the reason the bike stalls and then cannot run the starter. 13-14 volts at 5000 rpm is good enough to charge the battery and should have given you a fully charged battery by the time you got the bike home. What battery voltage do you get at idle after a few minutes running at 4000-5000 rpm, if the voltage drops dramatically to 12 or lower at idle I would suspect a dud battery.

The reg/rec was connected. I did all these checks where I had soldered the wires together before I slipped the heatshrink over the joints. The battery was apparently replaced (according to ChrisJa2 who I purchased the bike from) in March. I bought the bike in May which means it could potentially have been sat for 2 months discharging. He did say he hadn't really used it. I think I need to do some more checks and get back to you guys. I'm not dead set on replacing the reg/rec straight away, I just wanted to know the general consensus on these eBay items. I guess I'll give them a miss considering Cammo's reaction.