AN MD88 CAPT RPTED THAT HE MISREAD AN ENG CHKLIST AND KEPT THE ENG RUNNING; WHEN IT SHOULD HAVE BEEN SHUT DOWN.

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ACFT HAD ART SYS (AUTOMATIC RESERVE THRUST SYS) INOP. MAINT DEFERRED. WITH SYS INOP; ONLY ALTERNATE OR MAX PWR TKOF ALLOWED. TKOF WT WAS APPROX 146000 LBS (MAX ACFT TKOF WT 149500 LBS) FOR FLT FROM CVG WITH FULL PAX LOAD. TKOF WT FOR ASSIGNED RWY 18L WAS TOO HVY FOR ANY OF THE ALTERNATE TKOF SETTINGS; SO A MAX PWR TKOF WAS NECESSARY. WHEN TKOF CLRNC WAS RECEIVED; ENGS WERE BROUGHT UP AND AUTOTHROTTLE ENGAGED AS THE ENGS ACCELERATED TO TARGET EPR OF 2.05. SHORTLY AFTER ENGS STABILIZED; ENG #1 N1 CREPT UP TO BTWN 102% AND 103%. AS AIRSPD WAS ALREADY ABOVE 100 KTS; THE #1 ENG WAS SLIGHTLY REDUCED TO BRING THE #1 N1 TO APPROX 99% AND TKOF CONTINUED. AFTER TKOF WHEN OUR WORKLOAD PERMITTED; WE RAN THE 'N1; AND/OR N2 OVERSPD' CHKLIST WHICH TOLD US TO MAKE LOGBOOK ENTRY OF AMOUNT AND DURATION OF OVERSPD AND CONTINUE ENG OP. WE UNDERSTOOD THE CHKLIST TO ALLOW AN N1 OVERSPD OF 103% WITHOUT AN ENG SHUTDOWN. MAINT WAS NOTIFIED AND TOLD US TO KEEP ACFT ENGS RUNNING WITHOUT CHANGING ACFT PWR FOR THEM TO TAKE ENG PARAMETER READINGS. WE ALSO MADE A LOGBOOK ENTRY OF #1 ENG N1 OVERSPD TO 103% (ROUNDED UP TO BE CONSERVATIVE) FOR APPROX 3 SECONDS. ON ARR AT THE GATE; MAINT BOARDED THE ACFT AND READ THE ENG PARAMETERS SHOWING A #1 ENG N1 OVERSPD OF 102.5% FOR 8 SECONDS. MAINT ADVISED ME THAT THE OVERSPD REQUIRED AN ENG CHANGE. IT DID NOT MAKE SENSE TO ME THAT WE WERE ALLOWED; BY THE CHKLIST; TO CONTINUE A FLT WITH AN ENG THAT REQUIRED A CHANGE OUT AFTER LNDG; SO I REFED THE 'N1 AND/OR N2 OVERSPD' CHKLIST ONLY TO NOTICE THAT THE 103% OVERSPD APPLIED TO N2 AND THAT THE LIMIT FOR N1 OVERSPD WAS 102%. IN OTHER WORDS; THE ENG SHOULD HAVE BEEN SHUT DOWN. I CAN'T EXPLAIN HOW OR WHY I MISREAD THE CHKLIST BUT DO BELIEVE THAT IF THE CHKLIST WAS DIVIDED INTO 2 SEPARATE CHKLISTS 'N1 ONLY' ON ONE AND 'N2 ONLY' ON THE OTHER; THAT THIS MISTAKE WOULD PROBABLY HAVE BEEN AVOIDED.