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Discussion Starter · #1 ·
Well I finding it very hard to start my bike today, I have been trying to start it for the past 3 hours and have checked mostly everything, compression (120psi), spark (not very strong), petrol is getting into the head etc. Well I was kicking the bike over and I am finding it is firing up for a second when the ignition is turned off WTF. But when I turn the ignition on there is no life in the baby. This must mean there is a short circuit somewhere, could any one tell me the most likely places???
Sorry this is on the wrong section as my bike is a dtr125 but I don?t seem to get many replies on the 125cc section.
Thanks
 

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i would think the most likely place is around the headstock. However, it could be any where, so start at one end and work backward.

have you tried to bump it? its not just your battery is on the way out?
 

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Mate the first thing I would do is change the
spark plug just as a matter of course.

I had the same problem not that long ago
starting checking all the wiring extra, which
was very time consuming and it turned out
to be the plug...new plug and started first
time.

Good luck
 

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Discussion Starter · #5 ·
I was thinking that but i have re-built the whole top end less that 2 weeks ago and have put in a fresh plug

I have just notice something with the bike that might be the cause of the problem, well from the red wire that comes out of the battery there isn?t a fuse, the two connectors are just joint together, does this mean I could have burnt out some of the electrical system.
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I'd done the same complete rebuild, which
included a new plug but I guess what with
trying to prime her and get the mixture
right it f***ked up the plug.

My bike is a 91 model and the wiring loom
at the front where the wires go into the
headlight housing were a bit chewed
and needed a complete re-vamp, brought
some new wiring blocks (around 65p each)
and gave this area a good overhaul.
 

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Discussion Starter · #8 ·
I have checked the plug, a little black and oily but isn?t too bad. I suppose tomorrow in the daylight I am going to have to see the extent of the damage if any to the electrical system. All the electrical connectors on the bike are in good condition; previous owner might have replaced it all. One thing, if a lot of current did flow through the electrical system would this of bugger up my CDI unit or will it be fine?
Thanks
 

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Discussion Starter · #10 ·
This is the odd thing i am getting a spark when it is turned on but a very weak one, but i am getting a stronger one when the bike is off? I suppose it has somthing to do with the fues but i havent had this problem before with this bike.
 

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ive only had it when ive rebuilt an ignition block wrong, what a pain in the arse that was!

it sounds like they could be shorting on each other, causing a complete circuit reguardless of the posistion of the lock.

Im fairley sure that DJunreal will be along shortley to give some real advice, he seems to be pretty tricked up with the electrics on these bikes.
 

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This is the odd thing i am getting a spark when it is turned on but a very weak one, but i am getting a stronger one when the bike is off? I suppose it has somthing to do with the fues but i havent had this problem before with this bike.
sounds to me like you have a wiring problem/resistive joint on the ignition system,i'd look closely at the kill switch/ignition switch,a 2-stroke will run without a battery so you can ignore the battery,it's not a good idea to run without a fuse but this won't upset the ignition system unless you have a short(you will more than likley notice this by the smoke and burning smell
)
on yam's i think a connection on the cdi is pulled down to earth via the kill switch/ignition switch to stop the engine(if there is a medium resistance short to earth somewhere you will see the symtoms youre getting)you could try dissconnecting the kill switch,see if it starts,if not,dissconnect the ignition switch and try again(if it does start,you won't be able,with both switches dissconnected,stop the engine........reconnect a switch or stall it)if there's no luck its time to get the meter out and start checking the circuit back the the cdi.also give all the earth's on the bike a good clean.
cheers
doug
 

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Discussion Starter · #18 ·
Hi I found the problem today, a ****ing wire running from the cutout switch was broken, fixed it now and the bike is running perfectly. I also got fresh pair of on/off road tiers today make the bike look 100x better.
Thanks for all your help yesterday
 

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If i'd been along earlier, I could've told you EXACTLY how your cut-off works


The ignition AND kill switches work by shorting a wire WHEN THEY ARE TURNED OFF.

This basically shorts the connection to earth rather than through the plug.

There is ONLY EVER one way that your bike will run without the key and/or killswitch, and that's if you end up breaking the link for those wires. If it's just reversed like yours seemed to be, it's almost certainly a bad bit of wiring around the switches.

Glad you found the solution - like I told people before, electrics is EASY
:D:D
 
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