Could any of you knowledgeable types please tell me what power these were supposed to put out?

Not how much power you can get out of them with fettling, just the average power when they came out of the factory please.

I've a Mercury MK2, putting out about 8.5ftlb on average and I'm trying to decide whether to take it apart and have a fiddle or not.

Any info would be much appreciated.

Thanks,
Steve.