115 Suzuki 4Stroke Compression

[Ecnadnus]

I've done a lot of reading about compression on outboards and the consensus is that a variance of 10-15% between the highest and lowest cylinder is acceptable but you wouldn't want any more than that. I've also read that it shouldn't be any more than 10PSI variance???

Either way, should I be concerned with a 2002 Suzuki 115 4-Stroke that seems to run very good, but has compression readings of the following:
175 / 170 / 155 / 175

The dealer and their mechanic indicate they have checked everything on the motor and she is a very strong performer. The previous owner indicates that he has never had an issue with it either and it has always performed very well and was serviced regularly.

Can you run an additive in the fuel to help improve compression?

Thanks in advance and I'm looking forward to some great advice on this one!!