Boss One-Way Unit / Pullstart Starter Pawl – For ATV Jianshe JS250, Baja 250cc

Boss One-Way Unit / Pullstart Starter Pawl – For ATV Jianshe JS250, Baja 250cc & Structurally Identical Models

The Mechanism for Emergency Starting – Ensures the Correct Engagement of the Pull Starter!

The Boss One-Way Unit, often referred to as the starter pawl or one-way clutch of the pull starter, is a small but critical mechanical component. It sits in the pull starter housing and ensures that the force applied when pulling the rope is only transmitted in one direction (to the crankshaft) to turn the engine. As soon as the engine starts or the rope is released, this pawl must immediately disengage. If this part is worn or damaged, the pull starter can slip or the rope may not retract correctly.

This Starter Pawl / Boss One-Way Unit is a very common standard replacement part in the 250cc range and is the precise replacement for models such as the Jianshe JS250 Mountain Lion and the Baja Wilderness Trail 250 (WD250-U) ATV, as well as many other structurally identical machines.

Product Details and Benefits

• Restoration of Starting Function: Ensures reliable engagement and disengagement during pull starting.

• Precise Mechanics: Guarantees the correct power transfer to the engine.

• Broad Compatibility: Common format for many 250cc machines from major and minor brands worldwide.

Important Note on Verification and Compatibility

Since this component was used in many different 250cc models, precise verification is essential. Please visually compare the item with your old part. Also, please pay attention to all article information such as dimensions and the shape of the pawls, to ensure the correct fit.

Installation Instructions (Intended as Guidance Only!)

Important Note: Work on mechanical starting devices can be complex, requiring spring tension and precise assembly. Anyone who is unsure or does not possess the necessary specialized knowledge should have this work carried out by qualified personnel. The following guide is intended only as assistance.

1. Preparation: Secure the ATV and turn off the engine. Remove the pull starter housing from the engine.

2. Disassembly: Disassemble the pull starter mechanism to access the faulty starter pawl or Boss One-Way Unit. Caution: A large spring is often tensioned here! Carefully release the tension.

3. Replacement: Remove the defective component and replace it with the new one. Pay attention to the correct positioning of all small springs, pins, and spacers.

4. Reassembly and Test: Reassemble the starter mechanism (possibly under spring preload). Mount the housing on the engine. Test the pull cord: The cord should turn the engine and then retract cleanly and completely.

Secure Your ATV's Emergency Starting Capability! Order the Boss One-Way Unit / Starter Pawl (Art. No. 069-300100)!