Mercury SmartCraft Troll Control Kit 8M0083439 with Y Harness
The Mercury SmartCraft Troll Control Kit allows you to set and maintain a consistent
engine RPM while trolling without continuously adjusting the throttle.
Use the dash-mounted + and – buttons to
increase or decrease engine speed while trolling. This makes it easier to maintain
a steady trolling speed as wind, current, and boat load change.
This is a genuine Mercury Marine factory OEM kit. Mercury part number
8M0083439 supersedes previous Mercury part number
879365K08.
Will This Work With My Engine?
✔ YES — If your Mercury engine is
SmartCraft compatible and uses
mechanical throttle and shift controls.
✖ NO — This kit is
not compatible with DTS (Digital Throttle & Shift)
applications.
Still unsure?
Send us your complete engine serial number before ordering, and we will verify
compatibility for you.
What Is Mercury Troll Control?
Mercury Troll Control allows the operator to maintain a selected trolling RPM
while the engine is running in gear.
Instead of repeatedly moving the throttle lever, the operator can use the
dash-mounted control to increase or decrease engine speed with the
+ and – buttons.
Maintaining a consistent trolling RPM can help keep lures and bait moving at a
steadier speed, especially when wind, current, or boat load changes.
This can be useful when trolling for:
- Walleye
- Salmon and trout
- Striped bass
- Offshore species
- Live-bait applications
Quick Compatibility Guide
|
Application or Feature
|
Compatibility
|
|
SmartCraft-compatible Mercury engine
|
Required
|
|
Mechanical throttle and shift controls
|
Yes
|
|
DTS Digital Throttle & Shift controls
|
No
|
|
Analog gauge installation
|
Yes
|
|
Installation with a SmartCraft junction box
|
Yes
|
|
Installation without a SmartCraft junction box
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Yes — Uses the included Y-harness
|
|
Separate SmartCraft gauge required
|
No
|
What Is Included in the Kit?
Mercury identifies the following components as included with the Troll Control Kit:
-
Troll Control switch with +, –,
and RPM indicator light
- Dash-mount housing
- Mounting spacer, when required
- Gasket
- Retainer nut
- 10-pin Y-harness for installations without a junction box
The included 10-pin Y-harness is Mercury part number
8M0042976.
The Y-harness allows the Troll Control switch and an analog gauge harness to
connect to the appropriate 10-pin SmartCraft connection when the boat does not
use a SmartCraft junction box.
How to Operate Mercury Troll Control
- Start the engine.
- Shift the engine into gear.
- Set the engine speed at idle.
-
Press either the + or – button to
activate Troll Control.
-
The RPM indicator light illuminates when Troll Control is active.
-
Press the + button to increase trolling speed.
-
Press the – button to decrease trolling speed.
Troll Control turns off when the throttle lever is moved to a different speed
or when the engine is shifted back into neutral.
The RPM indicator light goes out when Troll Control is no longer active.
SmartCraft Wiring Options
Mercury designed this kit to accommodate several different SmartCraft helm
configurations.
Boat equipped with a SmartCraft junction box:
The Troll Control switch harness connects directly to an available connection
on the SmartCraft junction box.
Boat without a SmartCraft junction box:
The included 10-pin Y-harness connects to the 10-pin connector labeled
Junction Box on the command module harness. The Troll Control
switch then connects to the Y-harness.
Boat equipped with analog gauges:
The analog gauge harness connects to the remaining connection on the included
10-pin Y-harness.
Dash-Mount Installation
This is a dash-mounted control and requires an opening to be cut in the dashboard.
Before drilling, check the area behind the dashboard for braces, cables, wiring,
or other obstructions.
The mounting spacer is only required when the dashboard is less than
12 mm or 1/2 inch thick.
Mercury provides separate drilling templates for installations with and without
the mounting spacer.
Important:
Always measure the printed drilling template before cutting the dashboard.
Printer settings can change the size of the template.
Installation Recommendation:
Mercury recommends that installation be performed by a person familiar with
Mercury Marine products and the recommended installation procedures.
🔧 BAM Tip
Customers frequently assume that every Mercury engine equipped with SmartCraft
uses the same Troll Control components.
This kit requires a SmartCraft-compatible Mercury engine
equipped with mechanical throttle and shift controls.
It is not compatible with DTS applications.
If you are uncertain which control system your boat has, send us your complete
engine serial number before ordering.
Frequently Asked Questions
Will this work with my Mercury engine?
This kit works with SmartCraft-compatible Mercury engines equipped with
mechanical throttle and shift controls. It is not compatible with DTS applications.
Does my engine need to be SmartCraft compatible?
Yes. SmartCraft compatibility is required for this Troll Control Kit.
Does this kit work with Mercury DTS?
No. This kit is not compatible with DTS Digital Throttle & Shift applications.
Does this kit work with mechanical controls?
Yes. It is designed for SmartCraft-compatible Mercury engines equipped with
mechanical throttle and shift controls.
Do I need a SmartCraft gauge?
No. This kit provides a standalone dash-mounted Troll Control switch.
Can this kit be used with analog gauges?
Yes. Mercury's instructions show the analog gauge harness connecting through
the included 10-pin Y-harness when required.
Is the 10-pin Y-harness included?
Yes. Mercury 10-pin Y-harness part number 8M0042976 is included with the kit.
Can this be installed with a SmartCraft junction box?
Yes. The switch harness connects directly to an available junction-box connection.
Can this be installed without a SmartCraft junction box?
Yes. The included 10-pin Y-harness is used for installations without a junction box.
How do I activate Troll Control?
With the engine running and shifted into gear at idle, press either the
+ or – button. The RPM indicator light
illuminates when Troll Control is active.
How do I turn Troll Control off?
Move the throttle lever to a different speed or shift the engine into neutral.
The RPM indicator light turns off when Troll Control is deactivated.
Does the kit include installation instructions?
Mercury's installation and operation instructions are available in the
Product Files section of this page.
Mercury Marine Part Number: 8M0083439
Previous Part Number: 879365K08
Engine Requirement: SmartCraft-compatible Mercury engine
Control Requirement: Mechanical throttle and shift
DTS Compatibility: Not compatible
Installation Type: Dash mount
Product Type: Mercury SmartCraft Troll Control Kit
