My 2015 ETEC 40 tiller, always starts right up but periodically quits running after about 10 sec. or so at idle. It will not re-start, engine rolls over but no spark. I can disconnect all power from the neg side of battery, then re-attach and tighten, and she fires right up. I have cleaned the post and all cable ends on multiple occasions and my threaded connection is tight. This issue has happened several times now. I am careful not to advance/touch the throttle prior to turning the key. For some reason, it goes into a mode where there is no fire going to the plugs. Is this an EMM problem? Otherwise the motor performs flawlessly. Any ideas.