Correct tach for 115hp Johnson

tbeaun

Seaman
Joined
Jul 16, 2005
Messages
59
Was just looking at tachs for my 1974 115hp Johnson which has an 8 pole system. I found a set of Faria instruments & asked the seller if the tach would work with an 8-pole alternator & he said no. Wondering why, I went to Faria website & found this little ditty....."Older model outboards (prior to 1977) may have the tach signal wire originating at the ignition system though they are alternator equipped. All alternator tachometers may be used on these systems by disconnecting the tach signal wire at the engine and connecting that wire to the unrectified alternator signal at the rectifier. Be certain the number of alternator poles match the tachometer pole setting of the tach."......Is there a tach to connect to this system without having to rewire the system?
 

Basscat 1

Chief Petty Officer
Joined
Feb 11, 2005
Messages
444
Re: Correct tach for 115hp Johnson

Buy an OMC tach. It is the best investment you will make on your boat. They are the most accurate tachs, otherwise whats the point in having a tach if it doesnt read correctly?<br />Be sure to set it on 4P.
 
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