Ktm duke 125 help!

Hi guys and girls. I'm in desperate need of some help. I tried to start the bike on the way to work and it wouldn't actually start but it was trying to turn over. The dashboard and the headlights were turning off when I pressed the ignition and then coming back on when I released it. I thought flat battery but that's been fully charged and not fully solved the problem. However now it will start after some trying and will rev fine until I release the throttle it will sit on idle for maybe ten seconds then die. I also sprayed some Wd40 around the ht lead as this fixed the problem last time straight away. When it did start the first time it was chucking out a lot of fumes from the exhaust but after some time revving that seems to have cleared up for now. Any help suggestions and knowledge will be truly appreciated

Thanks!

Just an update!

The bike is starting now and not cutting out idling but there is a hell of a lot of fumes out the exhaust again is this something that will clear up?

Hi dont really know the KTM 125, but have you had a problem with the fuel pump at all, I know your bike is EFI so could be a problem there, and I wouldn't spray WD40 onto the HT cable, unless its the Electrical kind

Yeah I have a bike minded friend who told me off for the Wd40 and said I should use something85 but can't remember what it was he said. Im not mechanically minded at all but I have never had a problem with the fuel line that I know of

Dont use GT85 either, if you have to clean on electricals use this one

https://www.wd40specialist.com/products/contact-cleaner

for some reason your getting too much fuel through to the cylinder, how is the air filter

I'd replace the HT lead . Damp weather like we're having now can play havoc with a dodgy lead . Hopefully it is designed to be detached from the coil as well as the plug . Just buy a metre of standard black HT lead , don't mess with silicon lead because it's soft and not so easy to fit .

Another update! Thanks for all your advice so far really appreciate it. It fired up first time this morning but was misfiring for a couple miles or so then stopped. Could this be due to maybe trying to start it so much yesterday? Ktms are apparently renowned for having shite electrics so it could well be a dodgy ht lead which may also explain its tendency to cut out now and again when I'm holding the clutch in and slowing down am I right?

Sounds more like an air/fuel problem - Have you checked the air filter?

I have a problem my KTM duke 125 has a problem spark plug was black I changed it now it fires up but runs like crap and when u put it in geare it cuts out but put it in N it starts again and u have to rev slow or it cuts out any help 

On 06/07/2022 at 12:39, Simon.duke said:

I have a problem my KTM duke 125 has a problem spark plug was black I changed it now it fires up but runs like crap and when u put it in geare it cuts out but put it in N it starts again and u have to rev slow or it cuts out any help 

Sounds like either it's way too rich or you've got a weak spark.