ok so i have read that originally mazda had recomended that most rotary engines be rebuild after 100k, but i see that many engines go for longer than that, off course not with the same power as before, but none the less run pretty strong, so my question is how would be the best way to know if your 13b is up for a rebuild?

 

I've never heard of that recommendation from Mazda.

A rotary needing a rebuild will show the same symptoms of a piston engine needing a rebuild. That is, smoke and/or lower compression.

 

run a compression check,if u pull 95psi on both rotors then u have a strong motor,if u pull under 95psi but over or at least 90psi ur good but a rebuild is in ur future and if u pull 90psi or less then ur ready for a rebuild

 

ok that sounds great but how would i perform a compression test on a rotary? i know how to do it on a piston engine but dont know how to on the rotary = (

 

u would check it just like a piston motor.screw the comp tester into the lower spark plug holes.remove the fuel relay.turn the key over.first u'll get 3 solid bounces then it'll come up to ur compression number

 

Don't bother with a compression check. If the engine runs well, starts easily and makes decent power, then compression is fine.

90 PSI is a healthy daily driven engine that is just starting to show it's miles. Lower then 75 and you start to run into issues.