Tach for Mark 58A for prop testing

[waali]

I don't need a dash-installed tach. A more modern one hanging from the cowl temporarily would be fine since the boat has rear-seat steering. I just need something to help me with prop selection. Cheap would be good, also.<br /><br />Thanks!!

 

[mixerjv]

Re: Tach for Mark 58A for prop testing

I'm curious on this as well, I have a Mark 58A as well and would like to mount a permanent tach.<br /><br />I assume I would run a wire from one of the two alternator legs to a modern teleflex morse tach. The question would then be what setting (6P maybey?) or does anyone know how many alternator poles the older 4 cylinder merc has?<br /><br />Or should the signal come from the kill wire on the magneto? Settings?