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Compression change after break in?

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Hi everyone! I want to ask you if you have noticed any compression pressure changes after break in process? Have anyone measured compression on freshly built engine and after some time?

(Just measured compression on 2 stroke after one hour of riding and it lowered by about 0.3 Bar. It was piston change and freshly honed)

Hello the compression should increase unless there was oil in the cylinder when first starting the engine

Regards Ross

You need to make sure the conditions are the same when you are measuring compression. That can be the difference maker...

As Ross and Shota said, there should be a slight improvement as the rings should be sealing a little better, and if there's a drop it may be due to changes in the test proceedure and/or conditions.

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