Here are some tips on how to tune up an air cooled Volkswagen. Most people can learn to tune up an air cooled Volkswagen engine with just a bit of practice. If your VW is getting harder to start and you notice less power and gas mileage or missing then a tune up is long overdue.
A tune up is important for any car, but it is even more so for an air cooled engine. An air cooled engine will vibrate much more than a water cooled one. This vibration will cause engine components to wander from optimal settings a little quicker. The better tuned your engine is the less it will vibrate.
When you tune up an air cooled Volkswagen engine you should follow the procedures in a particular order. Some systems are dependent upon other systems to operate properly. For example an accurate carburetor idle mixture cannot be achieved unless the compression, ignition system and valve clearances are correct. In addition, compression readings will be adversely affected by improper valve clearances. … Full Story »
Setting the timing is step 5 in the tune up procedure. Ignition timing is dependent upon the rest of the ignition system being set up properly. Accurate timing cannot be achieved unless you have sufficient compression, correct valve clearance, correct ignition point gap, correct spark plug gaps and the engine is at normal operating temperature.
Here are three different methods that can be used to set your ignition timing:
These steps apply to all methods:… Full Story »
Spark Plugs Replace or Clean and Re-gap?
Your spark plugs will not need to be changed at every tune up, however they should be inspected and replaced if necessary. Most of the time you can clean up your spark plugs, check the gaps and reset if needed and get more mileage from your plugs. Some mechanics will replace the spark plugs at each tune up, but that is really a waste of both money and resources. “Experts” recommend that you replace your spark plugs every 12,000 miles.
When you take out your spark plugs be sure to arrange them in a way so that you know exactly which cylinder they came from. The condition of each spark plug when it is first removed from the cylinder head will give you insight into the internal conditions of your engine. For example, if all your plugs are relatively clean except for one that is burned or covered with oil or build up you know you have a problem in that particular cylinder.
… Full Story »
If you have been following the tune up procedures your distributor cap is already off, if not then unsnap the clips and remove it from the distributor. There is no need at this point to disconnect the spark plug wires.
Pull off the rotor button and look at the tip. Is it burned, pitted or corroded?
Inspect the points. The contacts should be perfectly parallel and their surfaces should be smooth and clean. If the points appear burned the culprit is most likely the condenser.
As part of a routine tune up you will replace the spark plugs, ignition points, rotor button and condenser. You should also inspect the distributor cap and spark plug wires and replace them when necessary.… Full Story »
A compression test is a basic part of a routine tune up for an air cooled Volkswagen engine. With these instructions you can check the engine compression yourself.
Compression is a measurement of the pressure that builds up within a cylinder as the piston rises and both valves are closed. For the fuel mixture to burn properly a certain range of pressure is required.
The two main factors that affect compression are the condition of the piston rings and the valves. Obviously, the valves need to be fully closed on the compression stroke to avoid loss of pressure.
Before you check the compression the engine needs to be at normal operating temperatures. Let your Volkswagen idle until the engine is completely warmed up.… Full Story »
Step by step instructions on how to perform valve adjustments in an air cooled VW engine.
Maintaining proper valve adjustment will help your air cooled engine to run smoother and more efficient. Improper valve clearances are one of the primary core causes of mechanical and efficiency problems in air cooled engines. Due to the nature of the air cooled engine frequent valve adjustments will have a major impact on your classic Volkswagen engine’s life and performance.
If the valve clearances are too small the valves will remain open too long which will cause them to over heat. If clearances are too large the opposite will happen, the valves will stay closed too long and will interfere with the intake of fuel and exhaust of burned fuel. Either way, if your valves aren’t adjusted correctly your air cooled Volkswagen will not run smoothly. Read on to learn how to adjust your own valves.… Full Story »