Bosch ignition wire set for air-cooled VW Type 1 and Type 2 engines — Beetle, Karmann Ghia, and Bus through 1971 (Type 1 engine only). The OE-spec replacement for original Bosch spark plug wires that have hardened, cracked, or developed insulation breakdown after decades in a hot engine bay. Part #98-9986-B.

Why Bosch wires matter on a classic VW

Bosch supplied the original ignition wires on virtually every air-cooled VW from the factory. Aftermarket wire sets exist at lower price points, but they typically use thinner insulation, lower-quality terminal crimps, and resistive cores that don't always match the distributor and coil setup the way the original Bosch wires did.

For a restored or original-spec VW, Bosch wires are the correct choice — they look factory, fit factory routing clips, and last decades when properly installed.

Old wires are one of the most overlooked sources of running problems on air-cooled VWs. Symptoms of failing wires include misfire under load, rough idle, hard starting in damp weather, and visible arcing or "crossfire" between adjacent wires at night. If your wires are original or unknown age, replacement is cheap insurance.

Specifications

• Brand: Bosch (German OE supplier)
• Application: Type 1 air-cooled VW engine
• Sold as: Complete set (4 plug wires + coil wire)
• Part number: 98-9986-B

Fitment

• VW Beetle: 1949–1979 (all Type 1 engines)
• VW Karmann Ghia: 1956–1974
• VW Bus / Transporter: 1950–1971 (Type 1 engine only)
• VW Thing (Type 181): 1973–1974
• Dune buggies, sand rails, and kit cars running Type 1 engines

Will NOT fit: Type 4 engines (1972+ Bus, 411, 412, Porsche 914) — these use a different distributor cap, plug location, and wire length set. Also will not fit Type 3 with the unusual flat-fan engine layout if your Type 3 uses the alternate-routing style; verify your engine before ordering.

FAQ

Is this a complete set or just one wire?
Complete set. Four spark plug wires plus the coil-to-distributor wire — everything from coil to plug.

Will these work with my Pertronix or other electronic ignition?
Yes. Stock Bosch wires work fine with Pertronix Ignitor and similar electronic ignition modules. Some high-output ignition systems (MSD, Crane high-energy) work better with low-resistance wires; in that case, follow the ignition manufacturer's wire recommendations.

Are these copper core or resistive?
Standard OE-spec resistive core, matching the original Bosch wires. Resistive cores suppress radio noise and are correct for stock VW ignition.

What plug wire length goes where?
The wires are pre-cut to factory lengths for the Type 1 engine bay. Cylinder #1 (rear right facing forward) takes the shortest wire; cylinder #3 (front left) typically takes the longest. The set includes the right mix of lengths.

Do they come with new spark plug boots?
Yes — molded boots at both ends, plus the proper terminal ends. No assembly required.

Will they fit my dual-carb or performance engine?
If your engine still uses the standard Bosch distributor cap and stock plug location, yes. If you've converted to a different distributor or relocated the plugs, measure your existing wires before ordering.