- Cylinder Head: Make sure it’s flat. You can test this with a piece of glass and a flashlight. Place the head on the glass, and shine a light from the other side. If you can see the light between the head and the glass, you should bring it to a machine shop and have it flattened. Also check that the cylinder studs are tight and not distorted.
- Valves: I put grease (or something like it) around the valve seating area and then blow air though the manifolds. If the grease blows right off the valves don’t seat properly. Once again, the answer is “bring it to the machine shop”. They can take the valves apart, make sure they are not bent or excessively worn, and that the guide bushings are OK as well.
- Piston and Cylinder Wear: Measure these and compare them to the tolerances in the Heinkel Worskshop manual. If the piston is more than .15mm from the original size you should consider reboring the cylinder and using an oversize piston. This is not unusual; I’m running a 4th oversize piston on my engine.
- Rings: Measure for excessive play, replace if needed. Tolerances are listed in the manual on page 25.
- Clutch: I replace the cork plates, and suggest replacing the spring(s).
- Drive and Swingarm Chains: I look for excessive wear on the chains. I also check the deflection of the chains. If the swingarm chain deflects more than 1 ½ inches from side to side, then I replace it. To measure, stretch out the chain, lay it on it’s side, then check the deflection.
- Brass swingarm journals: Once again you are checking for side to side play. Let these go to long and your car will wander. It is also impossible to replace them unless you totally strip the cases, so now is the time to fix them!
- Sprockets: If the tips of the teeth on the gears are not uniform and are very sharp then you should replace the sprockets. Beware, replacing sprockets isn’t cheap!
- Rear Hub Driveshaft: Make sure the parallel grooves are not distorted (usually a sign of riding on a too loose hub) and check the threads (to make sure they weren’t overtightened). These shafts are available from the clubs as well.
- Crankshaft: Compare to the tolerances in the Heinkel Workshop Manual
- Dynastart: Lots to check here. There’s an excellent article in the Heinkel-Trojan Club Cruiser News Magazine on what to check and how to do it. I’ll mention that in a later article.
For small parts, I empty them bag by bag into the parts washer basket. If I’m unsure of how parts are going to be reassembled, I zip tie them together in their respective order. Small internal parts clean up nicely. Sometimes exterior parts need a special session with a toothbrush, but they end up looking good.
With everything clean and checked, I usually finalize a parts order. Once I submit the order I pack up my stuff in an orderly fashion and wait for the parts to arrive.