Hey fellow riders

I am the (un)lucky owner of a Hyosung GT 650 FI from 2008.

The last couple of months I've been experiencing a couple of problems with my bike. When letting of the gas the bike pops a lot, but that's probably from the exhaust not being with a DB killer and/or wool. When I've been driving for 10 minutes or more, it starts misfiring and stalling when coming to a stand still. Some times it feels like I'm driving on a single cylinder when accelerating. I have just disassembled the fuel items on the engine and inspecting them and cleaning them. No visible leaks, cracks or other things that could be the culprit. When applying the gas in neutral it doesn't keep the revs at the same level. The revs keeps going up and down even when giving the same amount of gas.

The spark plugs are new and inspected with no faults.

I was wondering if it could be the ignition coils?

Please help me figure it out

Regards, Emil

Okay... some progress.
Bad luck finding spark plug cables. out of stock nowhere to find in this country, gonna have to import some.

But I disasembly the fairings and airbox in order to remove the front coil and sparkplug and found something very interesting, can't be coincidence...

Removed the coil and inspecting it found this mark like some little burnt or melt:

pic1:


Then checked if that side was touching something and in fact was touching this harnessed cables, and the exterior cover melted:

pic2:


Unwrapped the melted tape/cover and the blue cable seems to be the most affected but looks only superficial, a flat spot where they were touching.

pic3:


Now im thinking: the coil heat melt it or in fact the coil insulation failed and an arc was formed there jumping to the cable generating the fault?

So now I measure the coils, spark plugs and cables and seem to be ok in resistance at least....
spark plugs looked ok but front one had little carbon flash-like near the connector on the ceramic, not much tho...

Measurments:


If I get this values this does not mean that they are in fact good right? it may have insulation problems to the outside where the cable insulation melt? too much coincidence?
So... im going to swap the coils front and back, and try the front placed one don't be in touch with cables again.
Now im going to wrap the cables and everything and try riding to replicate the fault with the coils swaped.

update:
ok went to a ride and the bike fails the same way. I dont know if placebo or not but i feel it runs gradually worse, and smells more fuel exhaust fumes.
Only option now is to replace the coil.

Hi,can someone please tell me what is the purpose of the little bulb underneath the main bulb in the headlight globe,i cant get it to light up on its own.It comes on with the low beam upon starting the bike or am i missing something?.

Right now I have strong suspicions about the plug wires. If arcs jump outside the insulation could explain some rough acceleration and ecu thinking coils are bad.  Monday will try to find good ones.

You can do both.
Find a 2013+ gt250r. Problem solved.