Hello.

Can anyone tell me what the compression readings for a 400 Scrambler should be. I tested mine last night after some problems in the weekend, and get 115psi. Is this normal? Help!!

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115 psi is good enough for it to run.

 

In the service manual, 115 psi is the service limit........in other words, it's time to rebuild.

 

*****. I rebuilt it 10 hours ago. This will be the third rebuild this year. Thanks guys.


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Any idea of what it should be after a rebuild?

 

Compression changes with elevation. If 115 lbs is the service limit, I assume that is sea level. If you live at 3500 feet, that will be down to about 105 lbs. This is why we shave the heads for high altitude.

 

Yep, I am at sea level most of the time. I had problems in the weekend with the belt and starter, and was at 5000ft then.