400 FSE will not idle when hot

[Gordonian]

Anyone any ideas about my hot idling problem. Tried the usual fresh fuel, new plug, cleaned the throttle body, had the injector professionally cleaned and tested. Con checked the engine sensors. All seemed ok. But still, after about 2-3 miles it starts cutting out at idle. Runs ok with throttle open. Does seem to get hot quite quickly. It starts easy enough and idles when cold. Starts fairly easily when hot but will cut out when throttle closed. Someone said coil pack but I'm not sure. Do you think I need to get the software and lead and go down that route?

 

[fastisbetter]

Have u checked ur coolant level? Heating up quick could be cooling system related and if the sensor is not in an air pocket it can cause idle problems. Just grasping, I know

 

[Gordonian]

Coolant level is fine and even took radiator cap off and watched the coolant pumping round. Took the coil pack off today and con checked the coils. Primary was about 2ohms and secondary's both read 3100ohms. Also checked the plug lead but cannot get any continuity through it. Appears to be open circuit. Been googling this today and by all accounts I should get a reading of some sort. Could it be that I've got a break in the lead but with such a high voltage it jumps the break at higher revs but not at idle when hot? Or am I also clutching at straws.

 

[GGRider01]

That's a reasonable thought process. Get a new HT wire and plug cap. Or they could simply be loose. They screw together.

 

[Gordonian]

Got a new HT lead and plug cap and now running great. Been on an 8 mile and a 20 mile run and no problems. ( 20 miles in 28 degree heat). Lead and cap should read about 4.5K when con. checked.
Something else to be aware of !!!

 

[Gordonian]

Forgot to mention that I bought one of those cheap injectors from China. Waited about 3 weeks for it to arrive. It looked the business. Fitted it and bike started ok, ran for about 10 seconds then cut out and that was it. Never ran again. Avoid at all costs.