here is one answer from chatgpt...fwiw...just give it your engine mdl # for further details... see last parag.
Q 1987 50hp VRO can you list steps to do a link and Sync
ChatGPT said:
Sure
— here’s a
step-by-step “Link and Sync” procedure for a
1987 Evinrude/Johnson 50 HP 2-cylinder with VRO (same basic procedure applies for 48/50 hp models from mid-80s to early 90s).
The goal is to properly synchronize
carburetor throttle plates,
timing, and
throttle cam pickup so that fuel and spark advance happen together and the engine idles and accelerates smoothly.
Tools & Items Needed
- Timing light (12 V powered)
- Remote start switch (optional)
- Screwdrivers and wrenches
- Tachometer (if available)
- Factory service manual (recommended for exact specs)
- Feeler gauge (for idle stop screw if required)
PREPARATION
- Warm up the motor — run on a test tank or flushing muffs until at normal operating temperature.
- Ensure idle timing, throttle, and cam adjustments are not tampered with yet — if they have been, you’ll reset them here.
- Throttle cable disconnected from the throttle arm (you’ll reconnect after syncing).
STEP 1 — Set Throttle Plates to Fully Closed
- With the throttle arm against the idle stop screw, both carburetor throttle plates must be fully closed, but not binding.
- Adjust the link rod between upper and lower carbs if needed so both plates close simultaneously.
STEP 2 — Set Cam Follower Roller to Pickup Point
- On the throttle linkage, there’s a plastic roller that rides on a cam marked with an engraved line.
- With the roller just touching the cam, rotate the throttle slightly.
- The roller should align exactly with the scribed line on the cam when the carb throttle plates just start to open.
- Adjust by lengthening or shortening the throttle cam link rod.
This ensures timing advance begins exactly when carbs start opening.
STEP 3 — Set Ignition Timing (at full advance)
- Put the motor in forward gear (important for correct timing) and run it safely on muffs or in a tank.
- Advance the throttle to wide open while cranking (not running).
- Using a timing light, check maximum spark advanceagainst flywheel marks.
- Typical spec for your engine: 28° BTDC (check your specific model tag or manual).
- Adjust by moving the timer base stop screw until the light shows the correct value.
Do this
cranking only, not running, for safety unless the factory procedure specifically calls for running.
STEP 4 — Idle Timing & Speed
- Return throttle to idle.
- Start the engine and adjust the idle timing screwso it idles smoothly at:
- 700–750 RPM in gear (in water)
- ≈900–950 RPM in neutral
- Adjust air mixture screws on each carb (if adjustable) for smooth idle—turn slowly in or out 1/8 turn at a time.
STEP 5 — Reconnect Throttle Cable
- With the control box in neutral and the throttle lever at idle, adjust the cable barrel so the throttle arm rests just against the idle stop screw without moving the linkage.
- Lock the barrel nut.
STEP 6 — Final Check
- Advance throttle slowly—verify:
- Timing advances smoothly before full throttle.
- Throttle plates reach fully open at full control travel.
- No binding or lag between carbs.
If all’s smooth → you’re
Linked and Synced 
Would you like me to include the
exact factory specs (timing degrees, pickup point mark location, idle RPM, etc.) for your
1987 50 HP model number (e.g., E50ELCUD or J50TLCDC)?
That’ll let me post precise numbers instead of general ones.
You said... :
yes
ChatGPT replied :
Perfect
— I’ll give you the
factory link & sync specs that match your exact model.
Can you please confirm the
full model number from your engine’s ID plate or transom bracket?
It should look something like:
- E50ELCUD (Evinrude 50 HP, Electric start, Long shaft, 1987)
- or J50TLCDC (Johnson 50 HP, Tiller, Long shaft, 1987)
Once you give me that full model code, I’ll list:
Idle timing (° BTDC or ATDC)
Maximum timing advance
Cam pickup setting
Idle RPM (in gear & neutral)
Specific notes for VRO-equipped models
Can you read that tag for me? It’s usually on the
port transom bracket or the
core plug (round aluminum freeze plug on top of the block).
