Polaris ACE 150 EFI (2018 year). Manual - part 17

73

MAINTENANCE

Valve Adjustment Procedure

NOTE:

In order to properly set the valves, the engine must be at TDC on the 

compression stroke. To find TDC on the compression stroke, roll the 

engine over until the intake valve closes and stops at TDC. 

Intake Valve Clearance Adjustment

1. Remove the valve cover.
2. Verify cam lobes are pointed down.
3. Insert correct thickness feeler gauge between end of intake valve 

stem and adjuster screw.

4. When clearance is correct, hold adjuster screw and tighten locknut 

securely. 

5. Re-check the valve clearance.
6. Repeat adjustment procedure if necessary until clearance is 

correct with locknut secured.

MEASUREMENT

Valve Clearance

0.004” (0.10 mm)

74

MAINTENANCE

Valve Adjustment Procedure

Exhaust Valve Clearance Adjustment

1. Remove the valve cover.
2. Verify cam lobes are pointed down.
3. Insert correct thickness feeler gauge between end of exhaust 

valave stem and adjuster screw.

4. Loosen locknut and turn adjuster screw until there is a slight drag 

on feeler gauge. 

5. When clearance is correct, hold adjuster screw and tighten locknut 

securely.

6. Re-check the valve clearance.
7. Repeat adjustment procedure if necessary until clearance is 

correct with locknut secured.

MEASUREMENT

Exhaust Valve Clearance

0.0047” (0.12 mm)

75

MAINTENANCE

Constant Variable Transmission (CVT) System

Failure to comply with the instructions in this warning can result in severe 

injury or death.
Do not modify any component of the CVT system. Doing so may reduce its 

strength so that a failure may occur at a high speed. The CVT system has 

been precision balanced. Any modification will cause the system to be out of 

balance, creating vibration and additional loads on components.
The CVT system rotates at high speeds, creating large amounts of force on 

clutch components. Extensive engineering and testing has been conducted to 

ensure the safety of this product. However, as the owner, you have the 

following responsibilities to make sure this system remains safe:
• Always follow all recommended maintenance procedures. See your 

POLARIS dealer, or other qualified person, for service and repair assistance.

• This CVT system is intended for use on POLARIS products only. Do not 

install it in any other product.

• Always make sure the CVT housing is securely in place during operation.

CVT Drying

There may be some instances when water is accidently ingested into 

the CVT system. Use the following instructions to dry it out before 

operating. The drain plug is located on the bottom of the CVT cover.
1. Remove the drain plug. Allow the water to drain. Reinstall the 

drain plug.

2. Shift the transmission to neutral. Set the parking brake.
3. Start the engine. Apply varying throttle for 10-15 seconds to expel 

the moisture and air-dry the belt and clutches. Do not hold the 

throttle wide open for more than 10 seconds.

4. Allow the engine RPM to settle to idle speed.
5. Test for belt slippage. If the belt slips, repeat the process.
6. Your vehicle requires service as soon as possible. Your POLARIS 

dealer can assist.

NOTICE: Exposure to salt water will cause corrosion to metal components. If 

your vehicle is operated in salt water areas, rinse it off frequently 

with fresh water.

WARNING

76

MAINTENANCE

Filter Systems

Air Filter

Always change the air filter at the intervals 

outlined in the Periodic Maintenance Chart 

beginning on page 57. Access the air box 

near the right rear wheel.
1. To remove the air cleaning element, 

unlatch each metal clip holding the 

cover in place.

2. Remove the air filter element.
3. Clean away any oil or sediments in the 

air box.

4. Apply a commercially available chassis 

lubricant to the inside lip of the new air filter. 

5. Install the new filter.
6. Reinstall the cover and secure the clips.

NOTICE: Never operate the vehicle with the filter element removed. Dirt will 

enter the engine, causing rapid wear and severe damage to the 

engine.

Metal clips