Forums 🚥 PiT STOP 🔧 Hyosung Technical Help GT250 EFI 2013 Sluggish Starts. Reply To: GT250 EFI 2013 Sluggish Starts.
@MARCEL, Thank you for your comments. Although my bike is a 2013 bike, due to various problems I have had with it, it has only about 26000km on the clock. Since your suggestion to inspect the sprag-clutch entails dismantling the whole engine I will leave this as a last resort. I have done most of the other things you have suggested including removing the cylinder heads and decarbonising and rebedding the valves, replaced the coils, plugs and ht cables. I was even lucky to purchase, at a very low price, a second hand ECU which was never used due his bike getting stolen and changing this had no effect either. I have changed the fuel filter inside the tank, checked the ISC, cleaned the injectors all to no avail.
Since besides the sluggish starting I am still facing issues with the engine beginning to miss after about 15mins working and eventually it stalls completely, that is why I am turning my attention to the operation of the pickup coil.
So far I have found very skimpy information on the internet re answers to the questions I posted earlier. There are a couple of sites involved in the building of ECU’s for racing motor bikes which discuss this vaguely.
Some proposals include the ECU sending a pulse on BOTH plugs at startup and then monitoring the peak to peak timing of the pick up coil pulses shown in yellow above. The theory being that at the point that the peak to peak time is longest that particular cylinder is in the compression stroke phase. This sounds quite tricky to me. Others seem to somehow monitor the MAP sensor but this method seems even more vague to me.