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Discussion Starter · #1 · (Edited)
I recently had a piston seize, while on the mechanics stand. Besides the obvious, I am concerned about the damage to the crankshaft bearings. Everything I read says that seizures can accelerate bearing failure. Any thoughts.
 

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This is strictly a personal opinion, but Wiseco's are not my favourite pistons. You have to be careful and measure the actual piston before you bore the cylinder.
You have to run forged pistons (if that's what they were) much looser then cast ones. This sounds like what may have happened in the first instance. Or the ring gap wasn't properly set.

As far as a problem developing over time, the higher the CR the harder it is to keep the bike from detonating, in particular with stock squish heights, and this will cause all sorts of issues.

When the cylinders are removed one can get somewhat of an idea on the condition of the bottom end. Generally one would be more concerned about detonation then just a piston seizure, but it is a judgment call.

The oversize wasn't .001", maybe .010"

These are just general thoughts as it is impossible to even form a theory without seeing the parts.
 

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Discussion Starter · #3 ·
Hippo
Thank you for your thoughts on my problem. I am going to inspect the lower end as best I can, while apart. Everything I read says that when a engine seizes it can easily destroy the crankshaft bearings.
The combustion issues are a bit out of my league, but I am a good listener.
blair
 
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