If i can't feel any play in the connecting rod to crank bearings after pulling the top end is that it? Is there something more specific?

2002 Rancher 350

 

I have never known a 350 need anything doing to the bottom end. I must have done 50 or so top end rebuilds on them usually because they only hold 2 litres of oil and owners run them dry of oil. The small end bearing seizes or the piston (or both) when run dry.

 

Thanks. It smokes pretty bad and I think I hear a knock. Might be piston slap?
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As soon as I finish my swing arm rebuild I'm removing the top end.