I have just stripped down my motor as it has lost compression on the front and rear rotor,everything is fine except the tip seals have warped like a banana in the middle part of the seal,what could of caused this as i have never seen this happen before,thanks Roy UK.

 

There're a couple of things that can cause that . Excessive heat is one of the main reasons for warped seals.
Too lean a fuel mixture, timing too advanced, excessive coolant temperatures for operating conditions just to name few. Depending on apex seal design extended high rpm operation also can play a role.

 

The seals used are Mazda 12a 3mm Two piece items,also could excessive intake charge temps cause this aswell?