TOPIC: Old tach pulses

I have a older aqua meter tach that matches the instruments already on the dash. Running a '67 Johnson Golden Meteor 100hp. This is the engine that Bruce helped me convert from CDI to point/coil ignition. The motor runs great without problems.
The gray wire from the engine is still in place. Did the conversion from the gen 1 cdi change anything that would affect the tachometer install? The back of the tach is adjustable for pulse, 2/4/6 etc. It was removed from a 1973 135hp starflyte with cdi and was set at 6 pulses. I'll post some pictures if needed.
Thanks,
Cal

If you can count the poles on the alternator, you can divide that number in half to determine what pulse setting to use.
The attached picture of a Mercury stator (alternator) is a (12) pole stator, so the tach would be set on 6P.
Some tachometers might have an option:
"12 pole alternator use setting 4"
doc

Cal,

As the Doc says - your best bet is to run a tachometer that "reads" pulses from the alternator. If your engine is indeed a '67, the flyeheel is very flat like a Frisbee. It will be aluminum with a steel ring gear. The stator is indeed 12 pole, the 1st engine from OMC to use such an arrangement. The lead from the tach needs to go to one of the AC outputs from the stator BEFORE the rectifier. This will be difficult on a stock engine with the plastic plug that goes to the rectifier pack. You will need to splice into one of the leads from the stator. The insulation on them may be failing anyway. I have taken the stators on OMC and Mercury engines and cut the terminal ends off. Carefully removed all the crumbly insulation form the leads, then slipped motor "spaghetti" over them to insulate them. "spaghetti" is an old term for woven fiberglass sleeving used on electrical wires. Primarily used in electrical motors. Fireproof, tough as hell, Very flexible...wonderful stuff. I cut the "spaghetti" just long enough to leave the needed bare wire for a new end terminal. On the stator end, I drizzle a little JB weld onto the point where the new sleeving ends at the stator coil. This keeps it as clean as the original wire. This stuff will never rot. If you are really particular, use a little shrink tube at the end terminal transition to the woven fiberglass sleeve.

You can go to a motor rewind shop as ask to buy a few feet of "spaghetti" from them - otherwise you may need to buy an entire roll. I can assure you, it is superior to shrink tubing.

I then attach a barrier terminal strip to the motor (like the later 70s motors had, and attach all of the motor wires to the strip. I do away with all the stupid plastic connectors, including the one to the control box. Done correctly, the setup will be way more reliable than the original method of connectors

Thanks Bruce and "doc". I knew I could count on you.