Tuned fuelling

JOB INFO TOOLS NEEDED 22mm Lambda sensor extraction socket; bench grinder (optional); die grinder or electric drill; drill bits 0.5-0.75mm; file; hammer; pillar drill; screwdrivers; spanners 6-13mm; Vernier calipers MATERIALS USED Clean cloths; disposable gloves; emery paper; M6-8 bolt; paper towel; sanding band; wet and dry paper TIME TAKEN 1-2 hours COST DIY £5+ The single Solex carburettor on many air-cooled engines can be mildly modified to help improve performance at low rpm (e.g. when setting off) and provide a smoother delivery of power. Don’t expect a neck-breaking transformation in acceleration, but for the cost of some DIY machining, another 3-4bhp can be found, which is a reasonable improvement on a 40-50bhp air-cooled engine. We visited Bogg Brothers of North Yorkshire to see what they can do with a standard Solex 34 PICT-3 carburettor fitted on a 1600 twin-port in…