Sierra 18-5354 Distributor Cap, Replaces Mercury Marine 808483, for MerCruiser 350 MAG MPI 350/V-8

The Sierra 18-5354 Distributor Cap is a contact-controlled, standard-rotation distributor cap built for MerCruiser 350 MAG MPI 350/V-8 inboard/sterndrive engines. It is designed for New GM style module-in-cap distributors and is not intended for engines running Thunderbolt ignition or MPI engines equipped with an ECM 555. The cap is machined from metal with a white exterior finish and a twist-on closure that secures firmly to the distributor housing while allowing quick removal for tune-ups or spark plug wire service.

This distributor cap covers the ignition side of a full tune-up and is commonly replaced together with the contact set, rotor, coil, and spark plug wires when servicing a MerCruiser 350 MAG MPI ignition system. It measures 5.8 x 5.5 x 5.4 inches and weighs 0.33 pounds. Every Sierra part is built to meet or exceed the performance of the original equipment component it replaces, giving boat owners a reliable factory-fit alternative for scheduled maintenance or ignition repairs.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5354
• Ignition Type: Contact controlled distributor, standard rotation
• Ignition Exclusion: Not for use with Thunderbolt ignition
• Color: White
• Material: Metal
• Exterior Finish: Machined
• Closure Type: Twist-On
• Item Dimensions: 5.8 x 5.5 x 5.4 inches
• Weight: 0.33 pounds

Fitment

• MerCruiser 350 MAG MPI (GEN +) 350/V-8, model year 1998, serial number range L010019-L325962
• MerCruiser 350 MAG MPI MIE (GEN +) 350/V-8, model year 1998, serial number range L002008-L302199
• MerCruiser 350 MAG MPI SKI 350/V-8, model years 1995-1998, serial number range F350583-L304599

Replaces (OEM)

• Crusader 38070
• GLM 71400
• Mallory 9-29411
• Mercury Marine / MerCruiser 808483
• Mercury Marine / MerCruiser 808483T3
• Mercury Marine / MerCruiser 804418
• Mercury Marine / MerCruiser 808483T
• OMC 3854548
• Volvo Penta 3854548-9

Frequently Asked Questions

What engines does the Sierra 18-5354 distributor cap fit? The 18-5354 fits MerCruiser 350 MAG MPI (GEN +) 350/V-8 engines from model year 1998 with serial numbers L010019-L325962, the 350 MAG MPI MIE (GEN +) 350/V-8 from 1998 with serial numbers L002008-L302199, and the 350 MAG MPI SKI 350/V-8 from model years 1995-1998 with serial numbers F350583-L304599.

Will this cap work with a Thunderbolt ignition system? No, the Sierra 18-5354 is a contact-controlled, standard-rotation distributor cap and is not designed for engines running Thunderbolt ignition.

Is the 18-5354 compatible with MPI engines using an ECM 555? No, this distributor cap is built for New GM style module-in-cap distributors on V-8 applications and excludes MPI engines equipped with an ECM 555.

What OEM part numbers does the Sierra 18-5354 replace? It replaces Crusader 38070, GLM 71400, Mallory 9-29411, Mercury Marine / MerCruiser 808483, 808483T3, 804418, and 808483T, OMC 3854548, and Volvo Penta 3854548-9.

What material is the distributor cap made from? The 18-5354 is machined from metal and finished in white.

How does the cap attach to the distributor? It uses a twist-on closure that secures to the distributor housing and can be removed for tune-up service or spark plug wire access.

What are the dimensions and weight of the 18-5354? This distributor cap measures 5.8 x 5.5 x 5.4 inches and weighs 0.33 pounds.

Is the Sierra 18-5354 an original equipment part or aftermarket? It is an aftermarket Sierra replacement part built to meet or exceed the performance of the original equipment distributor cap it replaces.

What other ignition parts are commonly replaced along with this cap? On a MerCruiser 350 MAG MPI ignition tune-up, the distributor cap is typically serviced together with the contact set, rotor, coil, and spark plug wires.

Does the 18-5354 include the rotor or spark plug wires? No, this listing is for the distributor cap only; the rotor, contact set, coil, and spark plug wires are separate components.

Does the serial number range matter when ordering this cap? Yes, the 18-5354 is matched to specific serial number ranges on MerCruiser 350 MAG MPI engines, such as L010019-L325962 for the GEN + variant, so confirming your engine's serial number ensures correct fitment.