Dtr 125 knocking sound then seizes

[Mac999]

Hi guys, rode my dtr today all fine then a crunching/knocking sound comes from the engine. I turned if of then re started it but was seized. I then rocked it back and forth in gear and it unsiezed.restarted it but the noise was still there.
Basically I've had the head and barrel of and it all looks fine there is only a slight movement on the Conrad side to side
When I push the Conrad in the engine it fills smooth.
With no noise. Any ideas

[davebike]

Main bearings ? or big end ? hard to check with piston on con rod
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Dave
NC750Xdct + others at work !
davebike1@gmail.com

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As above ^^^^^, I'd say the big end bearing is breaking up. You can confirm that it's either big ends or main bearings by disconnecting the engine from the gearbox. Removing the clutch basket and cog should do this. With the barrel off turn the crank by rotating the flywheel and see how it feels.

What mileage has it done? Might be worth a new crank or a crank rebuild.
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