Having some dead battery reg/rec issues at the moment.

Bike wouldn't start the other day so i charged it and the Optimate said it was fully charged when finished. Plugged it into the bike and it reluctantly started (not as quick to turn over the starter motor as normal). After a minute or so of running i turned the bike off and when i went to start it again straight away, it was hardly turning over the starter motor with the lights dimming etc and the normal slow starter motor noise..

Took the battery out, plugged it back into the optimate and it said it was charged ok?
Would a dodgy rectifier drain a fully charged battery after a minutes running or is it just a knackered battery that needs to be replaced? If it was a dead battery wouldn't the optimate say it needed charging again?

Going to go over the rectifier with the multimeter tonight to check that but wondering if the battery should be replaced anyway. If yes would the YTX7A-BS Yuasa be the best or is there a Gel alternative that is better?

Sounds like your batterys knackered, but not always.

Measure the voltage across the terminals of the battery, and the voltage when your cranking it over.

A full test of the charging system is in order.. often older batteries die but you want to make sure the charging system isn't dead and killing the batteries.

Could also be crook contacts or leads;

Put your multimeter on voltage and go from negative terminal to a good contact on the motor and hit the startetr button.
If there is a much resistance from a poor contact or lead you will get a voltage reading, higher the resistance higher the voltage reading.
If you do get a voltage reading you can isolate the where the problem is using same method with multimeter e.g. one lead on frame and other lead on terminal bolted to fram ewil indicate how good that connection is.

Repeat the process on the power lead between positive terminal and starter motor terminal.


cheers
jon

i had this last week with my nc23 turned the ignition of 5 minutes later flat battery,,,,disconnect the battery and left it for half a hour it was back to 12.4 volts without recharging,,,replaced the regulator,,,problem solved did put the old one back in out of interest,,,,flat battery lol

Cheers for the help guys, just bought a new Yuasa battery and a new Yamaha Rectifier to replace the one on there at the moment incase it's knackered (always good to have a spare anyway).

In total those 2 bits only cost £35 (thanks ebay) so fingers crossed it's sorted this weekend

Ok still having no luck, stuck a new battery in and checked the regulator and those are ok
As soon as I touch the starter button the bike makes a slight click noise and then everything goes dead. The lights don't work and nothing happens until I unclip and reatach the battery again?

Anyone got any ideas what else to check? Checked all the fuses and those are still ok????

Julesholling wrote:The lights don't work and nothing happens until I unclip and reatach the battery again?

When you take the leads off the battery and then reattach them it works properly then??

That is strange... no idea why that would happen?

When the battery is connected i get lights working and lights on the dash, then i hit the starter there is a click and everything goes off. The lights then don't work and the dash lights go off until i disconnect and reconnect the battery. Then the same process the next time i hit the starter.

I have no idea where to start with this, does it sound like short circuit somewhere???

Julesholling wrote:I have no idea where to start with this, does it sound like short circuit somewhere???

Yes probably.

My logic would say that the starter relay is causing the short.

nc30 looms can be old and brittle, in this case it might be best to look at a wiring diagram, check all wires/connections that come from the starter relay for shorting signs. If nothing found, it might be time to strip your loom (or fit a decent used one, not a 5 minute job!).

Do you have any understanding of the electrical system (no offence intended)?

It might be quicker (but more expensive) to get an auto sparky to look at the bike. Take option 2 (fit a decent used loom) if unwilling to pay!

Goosed Battery or poor connection(s) somewhere.

Whats your battery voltage dropping to when you attempt to engage the starter?
I'm certainly no NC30 expert but I do design control systems - my logic would be the click is your starter attempting to engage, then a poor contact/connection somewhere won't allow the relatively high current inrush to operate the starter which kills everything else (lights etc) at the same time.

OR

Your battery although may be reading fully charged doesn't have the current capacity to engage the starter, tho if you have a new battery on there already I'd have a thorough investigation of your charging system

cheers

Dave