I purchased a 1996 Mariner 90 hp two stroke outboard serial OG360015. There was no manual with it and the aftermarket manual I bought doesn't list the amount of poles on the charging coil ? The tachometer on the boat was not working properly at the time of purchase. The tachometer I'm replacing was set for 8C/4P but I don't know if this was correct and not knowing what the poles are on the outboard I'm not sure what to set the new tachometer to. I'd appreciate any help Thanks.