1971 60hp rude

[wavrider]

What setting would I set the tach on this engine?
The settings on back of tach are 2, 3, 4, 5, 6,
Thanks for the replies

 

[jameskb2]

Re: 1971 60hp rude

Hi Wavrider,

I believe that's the 9 amp charging system, if it's like my '70 60 hp johnny.

The numbers on your tach represent "poles" on the alternator. Each pole has a north and south, (magnetic) and when the magnets in the flywheel pass by them, it creates a pulse (alternating current) that is then turned into 12v DC by the regulator / rectifier. (Diode switch)

So, if you count the poles on your stator, you'll find 12. Divide the pole count by two (for the north / south pass...to create a pulse) and you get 6.

Six pulses per revolution per pole. If your stator has 10 poles, then the tach is set to 5, and so on....

Easy breezy eh?

Best,

JamesK

 

[Joe Reeves]

Re: 1971 60hp rude

Six (6)

 

[HighTrim]

Re: 1971 60hp rude

In addition to what was already said, tachometers read off the alternating pulses from the stator. Any of the leads from the stator charging portion can be used for the signal. The designated tach signal wire is merely attached to one of those. Tachs have rotary switches on the back that set it to different numbers of coils in the charging circuit, times two because there is a positive and negative pulse for each coil for each cycle. Tachs measure pulses.

There is a reference chart at the bottom of this page for exactly determining this.

http://ww2.tflx.com/PDF/99320.pdf

 

[wavrider]

Re: 1971 60hp rude

thank you for the replies.

I know the v-4 were sit to 6, all I have been messing with the last few weeks are the crossflows so when I fired up the 3 cyl and hooked the tach up to it could not tell by ear how the rpm's were and had a used tach I was testing so thought I would ask if it was still 6. thanks for the replies.

 

[todster]

Re: 1971 60hp rude

I just bought an omc tach on ebay so am looking also. My o/b is a '71 50hp and the manual says a 9amp coil with 8 poles so I'm assuming the 60 is also the same so 4 would be setting right? My tach is a 175354 17dv and says for use on 5,6 and 10 pulse alt's use position 3 for 10 pul/rev. How do they figure that and what setting would it be at for an 8 coil stator?

 

[Joe Reeves]

Re: 1971 60hp rude

six