Polaris RZR 900XP Engine Rebuild Part 7: Engine Installation

This is the seventh and final part of our Polaris RZR 900XP engine rebuild series, in which we highlight the important points of a Polaris UTV engine reinstallation. 

Watch the video above and follow the steps below to complete the engine installation process of a rebuilt Polaris RZR engine. Use our Polaris RZR 900 parts diagrams for additional reference.

Polaris RZR 900XP engine rebuild installation

Tools and Parts - Polaris RZR 900 Engine Installation

  • Ratchet and extensions
  • Socket set
  • Spark plug socket
  • Torque wrench
  • Clutch alignment tool
  • Polaris transmission nut socket
  • Oil filter

Buy Polaris UTV drive belt

Buy Polaris UTV engine water inlet cover gasket

Reinstalling Ancillary Components to the Polaris RZR 900XP Engine

Before installing the engine into the chassis, you'll need to reinstall the spark plugs, water pump assembly, oil cooler, water inlet cover, oil filter, thermostat assembly and the throttle body adapters.

Step 1. Use a spark plug socket to install the spark plugs.

Polaris RZR 900 engine installation spark plugs

NOTE: A regular socket will allow the spark plug to drop down into the motor, which will bend the plug’s electrode so the gap will no longer be correct.

Step 2. Install new water pump O-rings and oil cooler O-rings

Polaris RZR 900 engine rebuild oil cooler rings

NOTE: Even if the old O-rings look OK, you should replace them now while the engine is disassembled.

Step 3. Line up the tip of the water pump with the grooved end of the oil pump shaft and reinstall the water pump assembly onto the engine.

Polaris RZR 900XP engine rebuild water pump assembly

Step 4. Remove all traces of old gasket from around the water inlets before installing a new water inlet cover gasket and thermostat gasket.

Polaris RZR 900 engine installation water inlet

Step 5. Inspect the throttle body adapters and their O-rings for wear, splits or tears and replace them if necessary.

Polaris RZR900 engine throttle body adapter

Remounting the Engine Into the Polaris RZR 900XP Chassis

Before the engine can be fully secured within the chassis, it must be properly aligned with the transmission. Once the motor is aligned, there’s a specific procedure that must be followed to tighten the mounting bolts.

Step 1. Apply anti-seize to the threads of the four engine spacers and jam nuts.

Polaris RZR 900 UTV engine installation

NOTE: You need to use a Polaris clutch alignment tool to correctly position the engine within the chassis.

Polaris RZR 900 engine installation clutch alignment tool

Step 2. Torque the threaded spacers to 10 foot-pounds, the jam nuts to 33 foot-pounds, and the through-bolts to 75 foot-pounds.

Polaris 900 side-by-side engine installation

Step 3. Use a Polaris transmission nut socket to tighten the jam nuts. The transmission nut socket is part# PU-50566.

Polaris RZR 900 engine installation jam nuts

Step 4. Torque the motor mount bolts to 40 foot-pounds.

Watch the clip below to see the remounting segment of our Polaris RZR 900XP engine rebuild video.

Installing the Polaris RZR 900XP Engine

Once the engine is remounted within the chassis, all the various hoses, cables and connectors can be reattached, including the oil and water hoses and the wiring harness. The oil system, exhaust system and intake system can also be installed and the engine oil and coolant replenished.

Step 1. Install a set of new exhaust seal gaskets

Polaris RZR 900 engine rebuild exhaust gas seal

NOTE: Don't reuse the old gaskets, since the exhaust header won’t seal to the cylinder head properly.

Step 2. Spray contact/brake cleaner into the throttle body adapters to make sliding the throttle bodies back into the adapters much easier.

Polaris RZR 900XP engine installation

Step 3. Raise up all the wires and hoses when reinstalling the inner clutch cover so they sit on top of the cover in the channel provided and aren’t trapped behind the cover.

Polaris RZR 900 engine rebuild remount

Step 4. Torque the drive clutch bolt to 96 foot-pounds and the driven clutch bolt to 40 foot-pounds.

Step 5. Install the drive belt with the arrows printed on it pointing to the left.

Polaris RZR 900 engine drive belt installation

Step 6. Replace the fluids, including the engine oil and anti-freeze

Watch the clip below to see the final installation segment of our Polaris RZR 900XP engine rebuild video.



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