Hello All, The smoke I referred to is the heat rising from the rear barrel, which if everthing is correct is not a problem but just an indication that the passing breeze does not readily hit the rear cylinder. Extra oiling is not a requirement just a good quality oil to lubricate without breakdown of the lubricating qualities. Many years we talked about this problem of rear cylinder heat and the fitting of an air scoop but the Doug being so close to the ground and lack of room not really an option. I dont have a problem with the rear heating because with nearly 3000 miles since the last rebuild, the compression is still OK and it still has a top speed of around 70 mph with the mods I have done to the engine. I have fitted 70mm pistons from a Kawasaki 1100cc many years back the compression height was too high so it was necessary for 1/8 spacers under the barrels. This made it difficult for the intake manifold but have got it fitting. I discarded the piston rod pin bushes and fitted piston pins with a tight fit into small end steel on steel. The pistons were then reamed out to a free fit for the new piston pins and fitted with Doug style bronze end pads. The Cylinders were bored on the lathe and polished to the desired effect and a little more clearance on the rear cylinder. The carby is standard B & B and the rear view mirror prevents the use of the air lever so it is just a matter of flood and kick. The magy is a BTH from a flat twin Army pump motor and is fixed timed at 40 degrees advance. The flywheel has about 1 and 1/2 inches reduced from the diameter. Out of all my bikes this is my preference to ride and like all Dougs with short suspension travel and its effect on rough roads, otherwise an enjoyable mount. more later, regards Al