Short Description / Project Description

In our workshop, we overhauled the SOHC engine of a 1982 Yamaha XT600 (47N) with kickstart. The project included the engine revision and refurbishment of the Mikuni dual carburetor (BST34 constant vacuum). The goal was to ensure the engine’s reliability while preserving its original adventurous character.

Analysis / Initial Condition

The XT600 engine had a defective rotor, worn gearbox teeth, weak shaft seals, a damaged ball bearing and needle bearing. The engine was already disassembled, with the gearbox partially repaired, but other weak points needed inspection and correction.

Work / Actions Taken

• Preparation of the engine: cylinder honing, valve lapping, inspection of other weak points
• Reassembly while preserving the slightly aged, original appearance
• Overhaul of Mikuni dual carburetor (BST34): ultrasonic cleaning, replacement of gaskets, needle and jets
• Functional check of rotor, gearbox, seals, and bearings

The work ensures a smooth and consistent engine operation, reliable throttle response, and proper battery charging.

Conclusion

After the overhaul, the Yamaha XT600 engine delivers excellent compression, smooth throttle response, consistent running, and proper battery charging. A refurbished classic that maintains the XT600’s adventurous character.