71mm Top End Rebuild Kit MOFANS for Yamaha Timberwolf 250

Description

Product Overview

The MOFANS 71mm Top End Rebuild Kit is engineered specifically for Yamaha Timberwolf 250 models produced between 1992 and 2000. Every component in the kit is manufactured from high‑grade cast‑iron, delivering exceptional strength and wear resistance that matches the original factory specifications. The kit includes a precision‑machined piston, a full set of piston rings, a wrist‑pin, circlip set, head gasket, base gasket, and a compatible spark plug, all packaged together for a complete top‑end overhaul.

Designed with a cylinder bore of 71.00mm and a stroke of 58.00mm, the kit restores the engine’s original displacement of 229.6cc and a compression ratio of 8.7:1. The cast‑iron material provides a dense, stable seal that minimizes compression loss and maximizes power output. Each ring is calibrated to a specific density, ensuring a reliable seal with minimal tightening effort, which translates into smoother engine operation and reduced risk of ring flutter.

Installation requires professional expertise, as the kit does not include step‑by‑step instructions. However, the components are engineered for straightforward assembly when handled by an experienced mechanic. The package dimensions of 8.5 x 8.46 x 7.64 inches and a weight of 5.77 pounds make it easy to handle and store, while the machined exterior finish reflects the high‑quality manufacturing standards of MOFANS.

Usage

This rebuild kit is ideal for riders and technicians who need to restore or upgrade the performance of a Yamaha Timberwolf 250. Whether the engine has suffered wear, loss of compression, or damage from prolonged use, the kit provides all the essential parts to bring the top end back to factory condition. It is particularly valuable for off‑road enthusiasts who demand reliable power delivery in demanding environments such as trails, dunes, and rugged terrain.

Because the kit is tailored to the specific dimensions of the Timberwolf 250, it fits seamlessly into the engine without the need for additional modifications. The cast‑iron piston and rings are compatible with the original cylinder bore, ensuring a perfect match that maintains the engine’s balance and vibration characteristics. This makes the kit suitable for both restoration projects and performance upgrades where durability and consistency are paramount.

Why Choose Us

MOFANS has a reputation for delivering high‑quality engine components that meet rigorous industry standards. Each part in the 71mm Top End Rebuild Kit undergoes strict quality control testing, including dimensional verification, material hardness checks, and performance simulations. This commitment to precision ensures that the kit not only matches but often exceeds the durability of OEM parts, giving you confidence in long‑term reliability.

In addition to superior materials, MOFANS provides comprehensive after‑sales support. Our technical team is available to answer installation questions, troubleshoot performance issues, and guide you through the rebuilding process. We also offer a warranty on all components, reinforcing our dedication to customer satisfaction and product excellence.

Key Features

• Strong cast‑iron piston delivers lasting durability and resistance to wear.
• Precision‑engineered ring set provides a tight seal with minimal tightening effort.
• Complete kit includes wrist‑pin, circlip set, head and base gaskets, and spark plug for a full top‑end rebuild.
• Designed specifically for Yamaha Timberwolf 250 (1992‑2000) ensuring perfect fit and performance.
• MOFANS after‑sales support and warranty give peace of mind for professional and DIY users.

FAQ

What engines are compatible with this kit?

The kit is compatible with Yamaha Timberwolf 250 models from 1992 to 2000. It also fits the Yamaha Bear Tracker 250 (1999‑2004) and Yamaha Moto‑4 250 (1989‑1991) when the original dimensions match the 71mm bore specification.

Do I need any special tools to install the kit?

Professional installation is recommended because the rebuild process involves precise torque settings and careful handling of the piston and rings. Standard engine rebuilding tools such as a torque wrench, piston ring compressor, and cylinder hone are typically required.

Can I use this kit on a modified engine?

The kit is designed for stock engine dimensions. If your engine has been significantly modified (e.g., oversized bore or custom cylinder), the components may not fit correctly. In such cases, consult with a qualified mechanic to determine compatibility.

What is the warranty coverage for this kit?

MOFANS offers a one‑year limited warranty covering manufacturing defects on all components. The warranty does not cover damage caused by improper installation, misuse, or aftermarket modifications.

How does the cast‑iron material compare to aluminum pistons?

Cast‑iron pistons provide superior wear resistance and thermal stability, which is ideal for the high‑compression environment of the Timberwolf 250. While heavier than aluminum, the added weight contributes to a smoother running engine and reduces the likelihood of piston slap.