How to Rebuild a 2015 Arctic Cat Wildcat 700 Engine

There’s something undeniably satisfying about taking a well‑worn Wildcat 700, stripping it down, and putting the pieces back together yourself. Whether you’re chasing that crisp “new‑engine” feel or simply avoiding a costly shop bill, a DIY rebuild can be a rewarding project. Below is a practical roadmap—tools, steps, and a few cautionary notes—to guide you through the process from start to finish.

Why Tackle the Rebuild Yourself?

Most owners hesitate because they assume the job is reserved for professional mechanics. In reality, the Wildcat’s 2‑stroke, 699 cc powerplant is designed for serviceability. A well‑executed rebuild can:

• Restore lost horsepower and smoother throttle response
• Extend the engine’s life by another 150–200 hours
• Save you anywhere from $300 to $600 compared to a shop rebuild

Just remember: the trade‑off is time, patience, and a willingness to double‑check every torque spec.

Gathering the Essentials

Before you roll the sled onto the lift, collect the following items. Missing a single tool can turn a three‑hour job into an all‑day hunt.

Tools & Equipment

• Metric socket set (10 mm‑30 mm) with a deep‑well extension
• Torque wrench (10–120 Nm range)
• Two‑piece piston ring compressor
• Feeler gauge set (0.1 mm–0.5 mm)
• Seal puller and a set of new gaskets/seals
• Cleaning brushes, lint‑free rag, and parts‑clean solvent
• Workbench with a sturdy engine stand (or a compatible Arctic Cat service cradle)

Parts to Replace

• New piston rings (factory‑spec for 2015 model)
• Re‑crowned piston (if wear exceeds 0.02 mm)
• Fresh cylinder liner (or at least a re‑bored liner)
• Crankshaft bearings
• Gaskets for the head, case, and exhaust ports
• Re‑gasketed 1‑inch exhaust pipe (optional but recommended)
• Fresh fuel filter and spark plug

Step‑by‑Step Rebuild Process

1. Remove the Engine

Disconnect the battery, drain the fuel, and remove the exhaust pipe. Unbolt the engine case from the frame, support the crankshaft with a jack, and carefully lower the assembly onto the stand. Keep the timing belt intact if you plan to reuse it; otherwise, replace it now.

2. Disassemble the Case

Start by loosening the case bolts in a criss‑cross pattern to avoid warping. When the case separates, note the position of the crankshaft journal and any markings on the cooling fins—these will help you reassemble correctly.

3. Inspect Critical Components

Look for scoring on the crankshaft, wear on the cylinder walls, and the condition of the piston rings. A quick visual check can tell you whether a full bore is necessary or if a simple re‑ringing will suffice.

4. Clean Everything

Use parts‑clean solvent and a brass brush to remove carbon deposits. Avoid steel wool; it can embed particles into the mating surfaces. After cleaning, wipe each part dry with a lint‑free rag and give the surfaces a final wipe with a lint‑free cloth soaked in fresh solvent.

5. Replace the Rings and Piston

Fit the new rings onto the piston using the ring compressor. Ensure the ring gaps line up opposite each other to minimize blow‑by. If the piston is scored, install the re‑crowned replacement now.

6. Re‑bore the Cylinder (if needed)

When wear exceeds 0.02 mm, a professional re‑bore is wise. If you have a re‑bore kit, follow the manufacturer’s instructions meticulously—measure the bore with a dial indicator after each pass.

7. Assemble the Crankshaft and Bearings

Lubricate the new bearings with assembly lube. Slide the crankshaft into the case, ensuring the timing marks align perfectly. Tighten the crankshaft bolts to the service manual’s torque spec—usually around 75 Nm.

8. Re‑join the Case

Apply a thin layer of thread sealant to the case bolts, then tighten them in a star pattern. The final torque should be within 2 Nm of the listed value; overtightening can crack the aluminum case.

9. Reinstall Ancillaries

Mount the fuel pump, carburetor, and exhaust pipe. Replace the spark plug with a fresh one, and double‑check the fuel line connections for any leaks.

10. Break‑in Procedure

Start the engine and let it idle for about five minutes, then gradually increase the RPM to 4500 over the next ten minutes. Keep the throttle steady and avoid full‑throttle bursts for the first 10‑hour run‑in. This helps the new rings seat properly.

Common Pitfalls and How to Avoid Them

Even seasoned mechanics hit snags. Here are a few that catch DIYers off guard:

• Skipping the seal cleaning: Residue can cause leaks that are hard to track down later.
• Using the wrong torque: Over‑tightening the case bolts is a leading cause of cracked housings.
• Neglecting the timing belt tension: A loose belt will slip, ruining the power delivery.
• Rushing the break‑in: Skipping the gradual RPM increase can lead to premature ring wear.

When to Call a Professional

If you encounter any of the following, it’s wise to pause and seek expert advice:

• Severe scoring on the crankshaft journals
• Cracks in the cylinder liner that you can’t sand‑smooth
• Unusual noises after reassembly despite correct torque values

In those cases, a certified Arctic Cat service center can save you from costly re‑work.

Final Thoughts

Rebuilding a 2015 Arctic Cat Wildcat 700 engine isn’t just about restoring power; it’s a hands‑on lesson in how a 2‑stroke engine lives and breathes. With the right tools, a solid parts list, and a methodical approach, you can breathe new life into your sled without breaking the bank. And when you hear that freshly rebuilt engine roar across the snow, you’ll know every minute spent in the garage was worth it.