Technical Sun Tach Experts ???

I have this vintage Sun Tach that I would like to convert from a 6cyl to 8 cyl.
First question, does this tach require a transmitter box? looks to me like it wires directly to coil negative like all modern tachs, but want to make sure!
Second, I read somewhere that adding a 15,000 ohm / 1/2 watt resistor on the sensing wire ( I****ume coil - ) is all that’s needed to convert 6 to 8 cyl. Does this sound right - is it that easy?
Thanks Ron

 

Actually on closer inspection of the tag I am seeing that tach is for 2 cycles …. I’m now thinking this one will be a wall hanger :/

 

I'm not familiar with any 2 cycle engines with 6 cylinders???

 

Im going with marine..

 

So if it was a 4 cylinder 2 cycle tac, would it work on a 4 cycle 8 cylinder engine? Or is my thinking totally wrong or backwards?

 

Send it to Williamson Instruments in Arkansas. He will fix you right up.

 

I'm thinking that it may not be marine as the rpm range is so wide...and marine application is low rpm compared to automotive....
cool tach and good luck

 

I know it's no help; but the only 6 cylinder/2 cycle engines that I have dealt with didn't have distributors. They did have blowers, tho.

 

Think Detroit Diesel, but at 8000 rpm that isn't a diesel tach.

 

Unlike what his name implies, Troublemaker is right on the money. Williamson did 4 of my tachs and each one came out perfect.

Pat

 

Thank you gentlemen for your insights. Looks like a total rebuild is the cure. Its a cool looking tach and will check out Williamson when I have decide to get it rebuilt.
Pat out of curiosity, what was the ballpark cost when they did your tachs.
Thanks,
Ron

 

I'd be lying if I told you as it was many years ago I do remember it was worth the price. They did several different jobs, one was a 10G to 8.5G conversion. Another from Battery to transistors.

Pat