BUGS BLOCK EPR PROBES ON B727 AT IND.

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ON CLBOUT AFTER INITIAL TKOF; THE CAPT CALLED FOR CLB PWR. AFTER SETTING CLB PWR ON THE N1 RPM GAUGES; I NOTICED THAT #1 AND #3 EPR SETTINGS WERE ABOVE NORMAL. THE CAPT ALSO NOTICED THE INCREASED EPR SETTINGS AS WELL. WE ALL AGREED THAT THE ACFT WAS SLUGGISH IN THE CLB AND THAT SOMETHING WAS WRONG WITH #1 AND #3 ENGS. ALL CREW MEMBERS DECIDED THAT THE #1 AND #3 EPR'S WERE INCORRECT BUT INVESTIGATION GAVE NO ANSWERS. ICING WAS NOT A FACTOR. WE DECIDED TO RETURN TO THE TKOF ARPT WHICH RESULTED IN AN UNEVENTFUL LNDG. FURTHER MAINT REVEALED CLOGGED EPR PROBES DUE TO INSECTS. WHEN INITIAL TKOF PWR WAS SET; I SCANNED THE ENG INSTS AND ALL APPEARED NORMAL. ABOUT V1; THE CAPT STATED THAT THE TKOF ROLL WAS SOMEWHAT LONG. SO I'M NOT SURE WHEN THE INSECTS ACTUALLY GOT INTO THE EPR PROBES. THE ACFT WAS FLOWN BY ANOTHER CREW WITHOUT INCIDENT JUST A FEW HRS BEFORE. WHEN ICING CONDITIONS ARE PRESENT; THE DATA COMPUTER CALCULATES MAX EPR FOR TKOF AND GIVES US AN N1 RPM SETTING AS A REF IN CASE OF ICED EPR PROBES. AS THIS INCIDENT SHOWS; ICE ISN'T THE ONLY THING THAT CAN CLOG EPR PROBES. I THINK WE NEED AN N1 REF FOR ALL TKOFS. THIS WOULD GIVE US AN ACCURATE INDICATION OF ENG PERFORMANCE.