Over the past two years I have restored a Douglas MK4. The machine is not entirely in its original state. The front fender is from the MK3. Apparently it was replaced decades ago, because the original gained a reputation to rotate with the wheel after a certain time. I got the motorbike with M-handlebar, DKW headlights and Tomaselli fittings. Obviously, one of the former owners showed sporty ambitions. Other than those provided in the series, even the rare sports camshafts were installed. As a tribute to this past, the Tomaselli fittings have remained and a small and straightened handlebar was mounted. Because the sport camshaft suffered from pitting, I got some normal camshafts from the Douglas Club Spare Departement.. Notwithstanding the series now a 7 inch headlamp is fitted (Original 6 1/2), so I can use with H4 35/35 watts instead of the Lucas-BIFOCUS. Last, I changed the passenger seat, which is normally fixed and feathered directly on the fender. Now it is mounted on a small luggage carrier. For my tours, I usually ride with saddlebags. For this reason, the original painted toolbars remained blank, the saddlebags are a little scrubby.
There were lot’s of rust, of course, but no holes. I had to bulge a lot, too. The frame is now powder-coated, the fenders very nice wet painted by a professional refinisher. Tank and small parts I have painted myself with 2K spray cans. The surface is gas resistant and the 2K paint is hard to be polished with a rotating disk. Therefore inclusions can be polished away. Frankly, I would not have thought that such good results are possible with spray cans. Technically the rusty "Radiadraulic" fork made a lot of effort, steering head bearing and the torsion bar spring on the other hand needed only new grease. The engine needed a total overhaul. The crankshaft was fixed by alpha bearings. As John Mark in his manual suggested, the machined oil groove now is blocked. The original way to give more oil to the timing gears will obviously cause a disastrous lack of oil for the crankshaft. Many other good advice came from London Douglas Motorcycle Club respectively the Douglas forum. Bing carburetors from the old Heinkel scooters are now responsebal for mixture preparation. The conditions in the cylinder and in the combustion seemed to be very similar me. As you know, it’s impossible to get original Amal carburettors. I'm curious to see how successful they will work.
I enjoyed restoring this bike, because of its high constructive quality claim. It’s true, in the of the post-war period due to cramp finances this claims sometimes got lost in production. But in my point of view, Mr. Douglas deserves respect. Great thanks deserve to Richard Bradley form the Douglas Club Spare Departement. Because I hat do restore the bike in a small garage, I had to go step by step not to overload my small workbench. I am afraid, my step-by-step-ordering caused a lot of work to him. Thank you very much, Dick!
