Replacing XTZ660 Crankshaft bearings
 

Hi,
I have taken apart the engine of my XTZ660 to clean and paint the crankcases which were badly corroded and give it a service at the same time.

I have split the crankcases and removed the crankshaft. I notice that the bearing on the left side has some wear in it and would like to replace it. However first I must remove the small gear which sits beside the bearing on the crankshaft. I presume this is an extremely tight fit and would need some heat to remove it.

The bearing on the right hand side is straightforward to replace.

Has anyone done this procedure and what technique did they use to remove that small drive gear.

I have access to a good engineering workshop which helps.

You need a puller.

The legs fit behind the gear, the threaded shaft presses against the end of the crankshaft (you may need to protect the shaft from damage from the puller depending on its shape) Then you wind it up and the gear is pulled off. It will help if you gently heat the gear to make it expand but don't get it hot, about 100-150'C is plenty.