Reply To: Just got my hands on “new” bike and I need help – GT250
1st pic is hard to tell but , focus on the ECU and relays first , then go down to the front, less headaches that way actually. Better to work from the back as connectors will be more self explanatory (rear eg = relays , lights , thats it. there is a 2 pin socket next to relay, leave it. and another 4pin socket hiding itself inside a black jacket, ignore)
If not, more pictures will explain it better.
2nd image = there is a little white plug with 1 brown and 1 green wire = Engine temp sensor ,
ET sensor sits at the front cylinder head under the throttle body.
Take your time. Also this may help (it is for a 650 but use it as a guide to follow where most parts connect to) (especially where it says “DASH CONNECTIONS”) https://hyoriders.club/forums/topic/wiring-tables/
You noted speedo problems. The link above ^ may verify your harness connectors towards the dash itself.
Then follow the wire colours down your harness, if a dash says “Blue/RED & GREEN” this is 2 wires in a 2-pin plug, it will say fuel gauge, find it on the harness and collect the fuel gauge sensor on the tank
Blue wire from the dash on its own (example) , might say “Neutral” , find it on the harness near the middle so it can reach the N Sensor on the engine, the N Sensor will have 2 wires , the extra wire is for the ECU + Signal to trigger the starting processing (not all 250’s have the same harness or ECU, hence again i can’t always give an easy answer but generally in my experience touching every ECU i got my hands on, DAEWOO is more fussy, very fussy! – excercise patience if you can and do 1 small thing at a 1 as it helps you study too )
I am sure this forum and manualsLIB already have 250 manuals with wiring diagrams at their last pages of the PDF documents. Or even look at the 2008-2009 650GT (It uses a daewoo ECU , only a few of of its parts will work on 250 , so it gets easier to follow. Ie. 650 EFi and 250 EFi early model use the same neutral switch , same clutch switch, the manuals will tell what colour wires they are. Other things like Fan Control, Thermo Switch, etc don’t apply to 250cc as it doesn’t use water cooling.
Hope this helps and good luck!