I was reading a thread from 2010 about another members engine failure problem that was exactly the same as mine that happened last week. I responded in that thread but thought I'd start a new one too as it is a quite old conversation.
I was riding two up through Belfast city centre, warm day and very slow traffic. At a majot junction the engine just stopped and the PGM FI light flashed. Pushed to side of road and it restarted after a few minutes but quickly began to feel like only one cylinder was firing then it quit again and that light flashed again. It wouldn't restart and there was an excess fuel smell.
I called my rescue service, got the SWing taken home and after I got her off the transporter she started and ran fine. I haven't had need or opportunity to ride her again since and am doing a little trouble shooting today on a day off.
I started her up earlier and she went fine, this is a week after the incident and she hasn't been used since. Idled fine, revved fine. Left her to idle and after a few minutes she began to splutter like on one cylinder. Switched off and restarted, same pattern and smoke produced from the exhaust. However, the F1 warning light did not flash.
Removed the spark plugs. Left cylinder plug was quite sooty. Right plug was also quite sooty but also wet. Cleaned both and replaced. Same thing happened - started fine and idled ok for a few minutes then sputtering. Swapped the plugs around and tried to restart. No joy. This time the F1 light flashed one long flash and three short ones, repeadedly. Also, there was no distinctive power-up whine sound of the fuel pump, So I guess it's a visit to Mr Honda, unless anyone has any ideas?
My SWing is a 2010 model, totally stock apart from GIVI windscreen and has been utterly reliable.