Bike running after key removed and now its dead!?

[Jafmandaddy]

coooooold....

I set of with a newly purchased commutor (second hand derbi senda 125.. yes yes I know but 90MPG!!!)

bike ran ok however when i pulled in for a refuel I turned the key and the bike stayed running. I pulled the key out ( lights all off OK) bike still running.. I had to use the choke to stop the engine.

I started the bike in the usual fashion and after a food stop it did the same again.

I reached my destination and it again had to be choked to stop the bike running....

all lights everything working as intended just simply not cutting out when the key is turned/removed

anyway I got up this morning and the bike was dead. no lights, no power not even a flicker.

had to bump it and hand signal my way around all morning.

I have checked both fuses 15amp and 7.5 amp and they are both fine. The battery was new a few weeks ago.

can anyone shed any light on this (poor pun)

what steps might I take to locate the problem and any likely culprits?


many thanks for your help in advance.

im a newbie so break me in gently

[mr jamez]

I'd say the most likely culprit is the ignition switch.
____________________
NSR 125F > BROS 400 > NC30 > BROS 400 > Trumpet S4 > '97 VFR 750

[herulach]

[lozzypop1]

Another vote here for worn ignition switch.
____________________
Funny, I used to hate being spanked as a child!
Tell me and I'll forget; show me and I may remember; involve me and I'll understand.

[Jafmandaddy]

The idle seems OK. it takes some time to settle but thats a given with the air temps of late.. once the chokes off and its warm its pretty steady and sounds right.

Im guessing Id better take it apart and test the connection?

any tips?

[i.p.phrealy]

you've not got/had an alarm on there have you? when water got in mine and I removed it nothing would turn the bike off. check if the previous owner removed the alarm.
____________________
it is impossible to lick your own elbow...
and if you just tried you need professional help.
Finally allowed a big bike 19/03/14!

[Jafmandaddy]

No alarm. Im taking the ignition apart now. ill let you chaps know. thanks for the advice.

[doggone]

Temporarily, does it not have a kill switch, using the choke sounds like a good way to create starting problems a few minutes later.

[YBR Ric]

The reason for having a dead bike in the morning was because the ignition hadn't been switched off (even though the key had been removed) and this drained the battery overnight.

Another (albeit a little late) +1 on having a faulty ignition switch.

[Jafmandaddy]

interesting.. what part of the ignition would be on if the dash and the parking light were all off?

[temeluchus]

[yaigi]

It's clearly haunted. It needs an exorcism that's what. Anything that stays running once you have switched it off is haunted IMHO.
____________________
What would you do in life, if you knew you could not fail?
Currently own - Fazer 600, 2000, Red. (But no riding as baby on board atm)

[dolly3900]

just solved a similar problem on the boys rieju.

cut lead from the ignition barrel .

re soldered and all now cool
might be worth a look

[Jafmandaddy]

OK folks. I dismantled the front end and found a white wire with a red stripe that was severed. In general the wiring looks like a monkey with a stanley knife has tried to lobotomise.

I have reconnected that wire and checked the wiring over and all is connected. I still get nothing when the key is turned. Im guessing you folks are right and the battery is flatter than a flat thing thats been stamped on.

I was hoping id at least get a feint indicator or a little noise when trying the starter button...nothing at all..

is the battery really that dead? is there any way for me to test this system using a car battery? or other source?

im lost now. maybe i could reassemble bump start and see if i can get some charge going for testing purposes?

any advice as ive got work monday and walking would leave me 4 inches shorter.

[Kickstart]

Hi

I don't know the Derbi ignition system, but on a basic crude ignition system the coil gets power and discharges when the earth is interrupted momentarily. The kill switch and kill function of the ignition switch work by providing a full time earth to the coil (hence the earth isn't interrupted and the coil doesn't discharge to create a spark).

Down side of this is where the power comes from. It is possible that the power may still be flowing to the coil with the ignition off, and with a full time earth there is still a fair power drain from the battery. This will flatten the battery over night easily.

I would 2nd the guess of a faulty ignition switch that others above have made.

Ignition switch often has contacts at the bottom which are connected or disconnected as the switch rotates. For example, fairly common for there to be 6 contacts (ie, 3 pairs), with maybe 2 pairs being connected and 1 pair disconnected when the ignition is turned on. Corrosion on some of these contacts can stop them working, and similarly the wrong lube could possibly provide a contact when there shouldn't be one.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[thomp1983]

if you've got a set of jump leads then yes you can connect the bike up to a car battery, this will allow you to trace 12v round the system, although i do suspect you've just got a really dead battery from it being left draining and it'll start fine with a jump start

chris

[Jafmandaddy]

again massive thank you for all your help here. it really does lift ones hopes.

i bumped it and rode it (on private land cough cough) for 10 minutes to see if the lights etc might show some inclination to work nothign.. so I will dissasemble the ignition switch you speak of and see if i can get the thing iluminated that way.

ill try the car battery to charge mine.. im guessing the car is best left turned off and not running?

[i.p.phrealy]

oh yes! don't start the car.
____________________
it is impossible to lick your own elbow...
and if you just tried you need professional help.
Finally allowed a big bike 19/03/14!

[Jafmandaddy]

Getting pissed off with it now. Anyone do arson?

I took the ignition switch apart cleaned the contacts (pretty clean already) and put it back together. The battery is charged, tested and working. Still no electrics whatsoever.

does anyone know what the white wire with red stripe is?

ignition has blue,green, orange and the stripey.

I am wondering if that white and red wire being severed has caused a component elsewhere to fail.

any way of me bypassing the ignition to see if I can get power to the lights?

I can strip a 2 stroke and rebuild it with my eyes shut but I really have no bloody clue about electrics whatsoever,

god loves a kick start and an oil lamp.

[thomp1983]

you need to get a multimeter (saw one in wilkinsons earlier for £10) or test light and follow the positive circuit from the battery and see what you find, you may find power isn't getting to the ignition switch for some reason (say a fuse you've missed). a wiring diagram will make your life easier aswell.

chris

[Kickstart]

[Jafmandaddy]

OK so the white and red wire I reconnected sorted the ignition not turning the bike off.

I bumped it and then used the switch and it stopped running.

1 down and thank you for helping me.

I knelt down to see if there was anything I may be missing and noticed slight plasticy smell.

and saw this.
https://img254.imageshack.us/img254/1894/bikemess005.jpg


https://img818.imageshack.us/img818/1627/bikemess006.jpg

hello nasty!

Im guessing this being sat on top of the head getting all hot and melty is not a good thing!

as im a moron regarding electrics can anyone identify the box unit its attached to and explain to me the best option to fix this?

I have a wiring diagram courtesy of these forums ( thank you very much indeed sirs) however Im looking at the diagram and scratching my head allot. dyslexia or retardation either or both!

And before you say it yes I will take a wire brush and some wd to that rust. Right after I solve the wiring, the high idle and change the oil.

buying second hand has never tasted so good.

[Jafmandaddy]

bike is in pieces, crimping kit ordered.

funeral to go to tomorrow ill be working through the night with fingers and pVC tape.

[thomp1983]

a decent picture would help, all you can see is a burnt wire near the fuel tap and some box. where is the box? what is connected to it? id guess it's a main power cable from it's size in which case you don't want to be bodging it unless you've found out what caused it to melt/burn in the first place

chris

[Jafmandaddy]

Picture is poor. palm meets face.

Ill try and do some tomorrow when the light is better and I can figure out the macro on the camera.

Luckily the ''box'' has no damaged wires and it leads to the ignition coil and looks OK. Im guessing its CDI?

OK so far I have 5 damaged wires


the ignition has

orange, green, blue, white and red stripe 3mm

the white and red stripe is the earth and it was severed/snapped and I have fixed this

the orange and green wires are severed/burnt/phewked


2 other wires smaller in diameter probably 2mm or 2.5mm

are also burnt/severed/phooked

1 leads to the tachometer the other leads to.. somewhere.. bulby could be oil light or something similar

could a damaged or poorly connected earth result in this frying wire scenario? have never rebuilt or repaired electrics in my life .

Im thinking of buying some thin walled automotive wire

3mm 39amp for the ignition wires and 2mm 25 amp for the bulb/tachometer


if im completely out of my depth here tell me ill sell my self down the docks and buy a loom.