76 LF tach in a 77 LF

[PolCat]

I put a 76 tach from a Liquifire 440 into a 77 340 Liquifire, why would it register
rpm but not where it should? Way lower than it sounds.

[JoeRainville]

PolCat,

There should be no difference between a 76-78 Liquifire tach. I believe all the Prestolite ignition sleds, including the 295/s, 340/s, CDI updated JDX-8 and 800's, All 76-78 Liquifire and Cyclones and the Liquidator all have the same, interchangeable tach. Motor size does not matter.

Is the ignition stock? And is the wiring OK?

-Joe Rainville

[PolCat]

I believe it to be original ignition, I bought it from the original owner. Will check the plug in wiring
to make sure of the connections.

[PolCat]

Quickest fix I ever had. Had the yellow/black wire on the yellow not the black wire. Tach needed a unregulated source I guess.
Cold idle will set when I get a better chance to warm it up.
Thanks Joe for the reply.