0581508 BRP Trigger Timer Base | Genuine Used Part

🔧 Product Description

Genuine Used Evinrude Johnson Two-Cylinder Timer-Base Trigger - Part Number: 0581508

A genuine pre-owned OMC, Evinrude and Johnson timer-base trigger for selected two-cylinder loop-charged outboards.

The two-wire trigger is mounted beneath the flywheel and senses crankshaft position. It sends the timing signal required by the ignition system to discharge the power pack and fire the ignition coils.

Part number 0581508 is most directly associated with selected 1976 and 1977 55HP engines, while replacement catalogues also group the trigger with related 50HP and 55HP two-cylinder engines from the 1970s.

⚙️ Key Features

• Genuine OMC, Evinrude and Johnson used trigger
• Correct OEM part number 0581508
• Two-wire timer-base sensor
• Designed for selected two-cylinder loop-charged engines
• Provides crankshaft-position and ignition-timing signal
• Service replacements and aftermarket trigger kits are available

🚤 Compatibility

Commonly used on

• Evinrude and Johnson two-cylinder loop-charged outboards
• Timer-base and power-pack ignition systems
• 50HP and 55HP two-stroke engine families

Direct verified applications

• Selected 1976 Evinrude 55HP models
• Selected 1976 Johnson 55HP models
• Selected 1977 Evinrude 55HP models
• Selected 1977 Johnson 55HP models

Broader replacement-catalogue family

• Selected 1971-1977 50HP two-cylinder loop-charged engines
• Selected 1971-1977 55HP two-cylinder loop-charged engines

Important fitment note

• Confirm part number 0581508 on the original trigger or timer-base diagram.
• Later replacement timer bases may use a different spark-advance lever.
• Do not install a replacement assembly without comparing the lever shape, wiring, resistance specification and mounting arrangement.
• The flywheel, power pack, stator, coils and mounting hardware are included only when shown or stated.

🔌 Function

The trigger generates an electrical timing pulse as the flywheel and crankshaft pass the required ignition position.

The power pack uses this pulse to release stored electrical energy to the ignition coils, creating spark at the correct point in the combustion cycle.

⚠️ Common Signs of Failure

• No spark on both cylinders
• Intermittent loss of spark
• Spark disappears as the engine warms
• Engine starts and then stalls
• Misfire at a repeatable engine speed
• Incorrect or unstable ignition timing
• Trigger resistance is outside specification
• Wires are cracked, pinched or corroded
• Timer base binds and cannot advance freely
• Engine will not achieve normal acceleration or rated rpm

🛠️ Service Notes

Recommended checks before installation

• Compare the wire colours and terminals with the original
• Measure trigger resistance to the factory specification
• Check trigger output with the specified peak-reading adaptor where required
• Inspect the wiring for insulation damage
• Check the timer-base bearing and advance lever
• Inspect the flywheel key and magnets
• Test the stator, power pack and ignition coils before condemning the trigger
• Route the trigger wires so they cannot contact the flywheel
• Set ignition timing and throttle synchronisation after installation

🔄 Supersession & Cross Reference

OEM Supersession / Service References

• 0581508 - Original timer-base trigger reference
• 581508 - Unprefixed OEM number
• 0385454 - Reported service replacement requiring the correct lever arrangement
• 385454 - Unprefixed service reference
• 0385457 - Related replacement reference reported with a different lever configuration
• 385457 - Unprefixed related service reference
• Replacement units must be matched by trigger wiring and timer-base lever configuration

OEM / Related Numbers

• 0581508
• 581508
• 0763805
• 763805
• OEM Description: Timer Base Trigger
• Product Type: Two-Wire Ignition Trigger
• Engine Type: Two-Cylinder Loop-Charged Two-Stroke

Aftermarket / Verified Equivalents

• Aftermarket trigger kit replacing 0581508
• Aftermarket trigger kit replacing 0763805
• Components Plus / compatible trigger reference: 133-0875K1
• Complete later timer-base assemblies may require changing or transferring the original advance lever

📦 Condition

• Genuine OMC, Evinrude or Johnson used part
• Pre-owned electrical component
• Cosmetic marks, wire ageing and light oxidation may be present
• Electrical testing before installation is strongly recommended
• Included wiring, lever and hardware are limited to those shown or described
• Supplied in protective or equivalent packaging