TAKUMI R5B12-77 Spark Plug Spark Plugs match for 243-4291 for Denso GI3-1 Champion FB77WPC C-U-M-M-I-N-S Q19G
Reliability is built, not claimed. Our production and QC teams work together to deliver spark plugs that perform consistently in the harshest conditions.
Product Overview
TAKUMI R5B12-77 spark plug is a form, fit and function equivalent replacement for OEM part 243-4291. TAKUMI R5B12-77 iridium industrial spark plug, cross-referenced to Champion RB77WPCC / Denso GI3-1 / Altronic L1863B family.
Every TAKUMI unit is produced in an ISO 9001 and IATF 16949 certified factory, 100% tested before shipment. The plug is engineered for long service life in continuous operation, with a nickel-plated shell, copper-core electrode and high-grade ceramic insulator.
Key Specifications
- TAKUMI TypeR5B12-77
- Thread SizeM18 x 1.5
- Reach20.6 mm (13/16")
- Hex Size22.2 mm (7/8")
- Seat TypeFlat
- Spark Gap0.3 mm
- Heat Range77
- Electrode TypeIridium / Double J
- ResistorYes
Cross Reference
- ChampionRB77WPCC / KB77WPCC / RB77CC / PB78WPC / RB77WPC
- DENSOGI3-1 / GI3-3 / GI3-5
- ALTRONICL1863B / L1863IP / L1863DP
- Federal Mogul / BERU18GZ4-77 / 18GZ6-77-2
- C-A-T243-4291 / 301-6663 / 194-8518
- WAUKESHA60999Z / 69919D / 69919Z
- C-U-M-M-I-N-S4098162
- GUASCOR7664292
Applications
- CAT G3500 series (G3508 / G3512 / G3516 / G3520)
- WAUKESHA gas engines
- C-U-M-M-I-N-S Q19G
- Industrial gas generators
Advantages
- Drop-in replacement - no engine parameter changes required
- Reliable ignition under high pressure and lean combustion
- Anti-corrosion nickel-plated housing
- 95% alumina insulator for heat and shock resistance
- Monolithic resistor for stable conductivity
- Factory direct with competitive pricing and short lead time
OE numbers are for reference only. Final fitment should be confirmed before ordering.
Factory & Quality Control
Our QC team records batch numbers for full traceability. Should any issue arise, we can quickly isolate the production batch and respond within 48 hours.
Production Workshop
TAKUMI runs a fully integrated manufacturing base: CNC machining, automated assembly and 100% functional testing under one roof.



From raw material to finished spark plug, every process is controlled in-house with ISO-certified procedures.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.

