I have a 107ci with decompression releases and a 1.8 terry starter, once in a while if I hold the start button to long (1,2,3,4 ) I get a load clunck noise !! starter turns the motor over fine for the 1,2,3,4, count then clunck !!

do you think it is the starter clutch working to hard ?? not able to turn the motor over any more and the clutch disengages (battery is all chagred up)

thanks