Hello. Is it bad for the engine to idle with the timing retarded? I like the slow percussive sound but would hate to be burning things up inside the combustion chamber (except for the petrol, of course).
They usually idle smoother with retarded ignition. At low revs on full advance it's often lumpy because the piston is effectively trying to be pushed backwards by the plug sparking BTDC. It takes higher revs to overcome this. The same reason you get a kickback on start up when you don't retard the ignition. Ron
