What tachometer do I need 1995 115

[lonegunman]

"I need a tach for a 1995 Merc

"I need a tach for a 1995 Mercury 115. I know the alternator is a 12 pole, someone told me the tach has to have a setting of 6P on the back for me to use it. Some of the tachs Im finding on ebay say they are good for 12 pole OBs but don't say anything about 6P.

What does the 6P stand for and will any 12 pole tach work?"

 

[ibnfshn]

"If they say it is good for 12

"If they say it is good for 12 pole, it should work. Majority of alternators are 12 pole and develope 6 pulses on each lead going to the rectifier. Thats why you can connect the tach to either lead (usually yellow) coming from the stator (alternator)."