Vintage Volkswagen Tune-Up Specs & Measurements

If you're getting ready to give your classic Volkswagen a basic tune-up or oil change, there are settings and measurements you're going to need to know. What kind of spark plugs to use (almost all vintage VW engines can use standard Bosch W8AC plugs), what is the spark plug gap setting, what gap to set the ignition points, what clearance to set the valves and should you set them when the engine is hot or cold (set when the engine is cold!). The chart below has answers to all of these questions, including how much oil you'll need to do an oil change and what degree setting to use when setting the ignition timing. In addition, if you need to buy a new battery and don't have the old one, the chart will tell you what Ampere/Hour rating to look for, and what physical size (posts not included) will fit in your bug or bus.

Firing Order
Spark Plug Type
Bosch W8AC (factory recommended Bosch W175T1 or Champion L87Y)
Spark Plug Gap
.024" - .028" (0.6mm - 0.7mm)
Ignition Points Gap
.016" (0.4mm)
Valve Clearance (adjust cold)
Intake = .004" (0.10mm), Exhaust = .004" (0.10mm). Before 1965, on 1200 & 1500 engines with the long rocker arm mounting studs,
Intake = .008" (0.2mm) and Exhaust = .012" (0.3mm)
6 volt: bug = 66Ah, bus = 77Ah,
6 volt dimensions: 8 1/4"w x 6 3/4"d x 6 5/8"h
12 volt bug = 36Ah, bus = 45Ah,
12 volt dimensions: 9 3/8"w x 6 1/2"d x 6 1/8"h
Crankcase Oil Refill
2.64 Quarts (2.5 Liters)
Transmission/Rear Axle Refill
2.64 Quarts (2.5 Liters)
Reduction Gear Case Refill
0.26 Quarts (0.25 Liters) per side
Oil Bath Air Cleaner Housing
0.26 Quarts (0.25 Liters)
Clutch Pedal Free-Play
0.4" - 0.8" (10mm - 20mm)
TDC Location On Crank Pulley
0.6" (15mm) to the left of the right-most notch
Ignition Timing (static)
1100/25hp bug: 5° BTDC
1200 bus: 10° BTDC
1200/36hp bug: 7.5° BTDC
1200/42hp bug: 10° BTDC
1300 bug: 7.5° BTDC
1500/51hp: 'G' case: 10° BTDC
1500/53hp: 'H' case: 7.5° BTDC
1500S/66hp: 'R' case: 10° BTDC
1600/57hp: 'B' case: 0° ATDC
1600/60hp: 'AD' & 'AE' cases: 5° ATDC
1600/65hp: 'T' case: 7.5° BTDC
1600/65hp; 'U' case: 0° ATDC
1200 bug: 50°
1300 bug: 42° - 58°
1500/53hp: 'H' case: 42° - 58°
1500/54hp: 'K' case: 50°
1500S/66hp: 'R' case: 50°
1600/60hp: 'AD' & 'AE' cases: 44° - 50°
1600/57hp: 'B' case: 47° - 53°
1600/65hp: 'T' case: 50°
1600/65hp: 'U' case: 47° - 53°
Generator Fan Belt Deflection
0.5" midpoint between the 2 pulleys
Engine Weight (no fluids)
Approx 242 lbs. (110kg)
Clearance Between back of shroud fan, and fan cover plate
Add or remove shims to obtain .06" - .07" gap
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Which carb is correct for your engine? Check the Solex Carburetor Model Numbers Table here.
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