would this be a good guide to follow when doing a compression check?

*115+psi is like new
*110-115psi is healthy
*90-100psi is getting weak (1 year or less in most cases)
*90psi and below could blow at any moment

*should not be more than a 20psi difference between both rotor's.


...i am trying to get everything i need ready to go look at a car this coming weekend.

thanks

 

I don't think 90 psi or less is 'blow at any moment'

There are plenty of cars running at 60ish compression if you spend the time trying to convince them to start up every now and then.

*115+psi is awesome
*95-115psi is good
*75-95psi is getting tired
*0-75psi looking at a rebuild sooner rather then later


FYI, the FSM, while being the standard, tends to favor higher compression numbers even though lower numbers are a-ok. Make sure you know how to do a correct compression test though.