www.zxrworld.co.uk

hi i have a zxr400L5 i have just put a new battery on it pulled over after a 100 mile journey and it wont start i put my friends battery on it and it runs fine but did the same i multimetred the battery when the bike was running and it wasnt charging at all any ideas its had a new regulator regtufier so could it be the generator ?

It could be a multitude of things from a knackered component to a loose connection to a broken wire. You need to find out which of these it is by getting to work with your meter and tracing the charging circuit all the way from the battery to the alternator. No other way to find out and wild guesses will only waste you time / money. Methodical tracing back is the way to go.

Have fun

Sounds like you have the same problem as me! I charged the battery overnight on friday, rode all the way from Yarm to Kielder reservoir on Saturday via Hexham, then the bike conked out on the way back towards Hexham. Turned the headlamps off and managed to bump it off (after finally getting it into second!) and made it nearly all the way back home - finally expired about quarter of a mile from my parents so pushed it there and bummed a lift home off mummy!! Bike was low-loadered back to my shed this afternoon and is on charge for work tomorrow! Eventful day! Will be testing and fixing over the course of the week and will share any findings )

Phil

alternator is easy to check (did mine yesterday), remove LH rear panel (the one with the fuel tap), you will see a connector with 3 black leads, going into 3 yellow leads, the black leads come from the alternator, the yellow leads go to the reg/rec...so should be easy to find/trace.

split that connector with the black/yellow wires, and remove the connector attached to the reg/rec. set your multimeter to the 1x Ohm setting and check for a resistance of 0 Ohm down each of the yellow wires, anything higher than a few ohms means that the wire has a break and will need replacing, or needs re-soldering to the connector.

connect the reg/rec back together, fire the bike up and either get a mate to hold revs at 4k rpm, or adjust the idle screw to hold bike at 4k rpm, then set multimeter to AC voltage (needs to be able to measure at least 70V AC) and test each of the three black leads (so you should take 3 readings from the three leads, 1-2, 1-3 and 2-3), manual say you should read 43V, mine was 49V which is fine, anything less than 43V and you might run into charging problems, anything a lot higher than 43V can potentially fry the reg/rec.

Top info Banner, cheers! Had her on charge all night and got to work ok, will test her tonight once the kids are in bed and I can escape to the man-cave!

no probs, let us know how you get on...its an easy thing to check, and as tirpitz says, go through everything bit by bit, wire by wire...ive recently checked almost all of my ignition system and charging system wiring trying to hunt down potential faults. got a couple of connecters to clean up, maybe a few to replace and re-solder, then pack it all with dielectric grease and it should be fine for a few decades to come

will definately keep you posted hopefully get a look at it tonight and maybe have a tidy of the mancave - got to make space for my next project: a 1967 Cotton Lightweight Trials bike

never got chance to have a proper look - by the time I got in the Man Cave it was a bit late for taking fairings off. I did fire it up though and put a meter across the battery terminals - it was reading nearly 19V!! A bit high methinks, although suggests the alternator is working! Going to have a fettle today - suspect it'll be the regulator/rectifier but will test everything from scratch and see what I find.

beermaker wrote:never got chance to have a proper look - by the time I got in the Man Cave it was a bit late for taking fairings off. I did fire it up though and put a meter across the battery terminals - it was reading nearly 19V!! A bit high methinks, although suggests the alternator is working! Going to have a fettle today - suspect it'll be the regulator/rectifier but will test everything from scratch and see what I find.

19V is deffo a dead reg/rec...will kill your battery very quickly if not sorted...it should be ~14.5V at 4k rpm and ~12.6V under no load (for a fully charged battery), under 12.6V and you have a charging problem, under 12V and its probably a dead battery.

oh dear..... took the side panel off and removed the rectifier/regulator. There was no plug into it, only wires with crimp connectors which had all melted into one semi-homogenous mass of metal and plastic. Well fmfl!! Reg/rec was held on with one bolt and has some bike breakers writing on the underside so has obviously been the victim of some cack-handed home mechanics hamfisted butchery at some point in the dim past. Presently sat on the with the telly on, a copy of the service manual, the reg/rec and a multimeter and waiting for my missus to get home with some booze!

beermaker wrote:oh dear..... took the side panel off and removed the rectifier/regulator. There was no plug into it, only wires with crimp connectors which had all melted into one semi-homogenous mass of metal and plastic. Well fmfl!! Reg/rec was held on with one bolt and has some bike breakers writing on the underside so has obviously been the victim of some cack-handed home mechanics hamfisted butchery at some point in the dim past. Presently sat on the with the telly on, a copy of the service manual, the reg/rec and a multimeter and waiting for my missus to get home with some booze!

checking the reg/rec really needs 2x12v battery's and some lights to test the circuits properly...best bet is to solder in some new connectors/6-connector block and get a replacement reg/rec just in case...

didn't get any testing done - my cousin came round and we sat talking farming for the evening instead! Ooooh Aaaaarrrr!! Have got a couple of 12V batteries in the man cave so will have a test later today. Going to remake wiring and connectors on the bike as the present ones are a bit toasty. Suspect it was probably crap wiring rather than the reg/rec but will test and reassemble and test again and if it's not right (14.6V into the battery) then I'll just get another unit for the bike

you might find that having a 19V potential between your battery terminals might kill the battery as well, so new reg/rec still might not show 14.6V, when you get new one test it will a confirmed battery.

cheers for the tip - I've got a battery off my old GS500 which is only 8 months old and has been kept "topped up" on an optimiser since the bike was written off so should be sound for testing

right - have remade the burnt out connections, tested the alternator (resistances ok, no shorts to each other or shorts to earth and puts out a good healthy 49VAC on each coil at 4000 RPM). Took the reg/rec off and cobbled together several batteries and followed the testing procedure - looks like the rectifier is OK but the regulator is paggered hence why it's putting nearly 20VDC into the battery. Will get a replacement but in the meantime - is there any harm in leaving it disconnected and running the bike on battery alone so I can get to work (obv. charge it up on an evening!)? I can't think that there would be but would appreciate if someone knows for sure!