I re-gapped my plugs the other day, to 0.7mm since I'm running on LPG. When I fitted them not long after I got the vehicle I left them at the standard 0.9mm, and I didn't really think that closing them up by a tiny fraction like that would help.

It's made a hell of a difference. I could hear straight away that it was idling better, and while the massive flat spot is still there between 2000 and 3000rpm on both petrol and LPG, it's a lot less pronounced. Definitely something worth checking.

Hmm, shame you posted it today when I'm back at work tomorrow rather than sitting around with nowt to do all day. I'll probably get a new set, regap them and whack them in.