Have a 78 25hp johnson, i hooked it up to an old nissan tach that was in the boat, tach works but i dont know what setting to put it on, it has to b 12 pole pretty sure only problem tach doesnt say which is 12, has a dial on back with 5 setting when turned i get pretty much all different ranges of rpm's even though a couple are real close, i looked for the tach on the internet and couldnt really find anything, anyone know how i can determine which is which?
much help would be appreciated am trying to find proper rpm's so i can determine what prop size to get.
running it on a 15 ft bomber marathon pretty heavy boat and dont think it is reaching optimum rpm's was going to go from 11" to 9" pitch if my rpm's werent to high.
much help would be appreciated am trying to find proper rpm's so i can determine what prop size to get.
running it on a 15 ft bomber marathon pretty heavy boat and dont think it is reaching optimum rpm's was going to go from 11" to 9" pitch if my rpm's werent to high.