Tachometer Correct?

Mad Mazda Midget · 10-05-2008, 05:16 PM

I am new to rotarys and not much of a mechanic. I had a Tachometer installed in my race car which has a 13b. I am wondering if it could be reading the wrong RPM. Is it possible, if it was installed wrong, that it is reading half of what it should be? Thanks for the help.

Rogue_Wulff · 10-05-2008, 06:05 PM

If it wasn't set for 4cyl mode, then yes. Most after market tachs come from the factory set for a V8. The rotary has the same ignition cycle as a 4cyl, firing twice per revolution.

Mad Mazda Midget · 10-06-2008, 05:57 PM

Auto Meter said the same. I pulled the meter and it is set wrong. I am going to verify how much it is wrong. My guess it was reading 50%. It only cost me a new motor. Well make that cost my shop a new motor.

10-05-2008, 05:16 PM	#1
Mad Mazda Midget The Newbie Join Date: Oct 2008 Location: Ellensburg, WA Posts: 3 Rep Power: 0	Tachometer Correct? I am new to rotarys and not much of a mechanic. I had a Tachometer installed in my race car which has a 13b. I am wondering if it could be reading the wrong RPM. Is it possible, if it was installed wrong, that it is reading half of what it should be? Thanks for the help.

10-06-2008, 05:57 PM	#3
Mad Mazda Midget The Newbie Join Date: Oct 2008 Location: Ellensburg, WA Posts: 3 Rep Power: 0	Thanks Auto Meter said the same. I pulled the meter and it is set wrong. I am going to verify how much it is wrong. My guess it was reading 50%. It only cost me a new motor. Well make that cost my shop a new motor.

10-05-2008, 06:05 PM	#2
Rogue_Wulff Non Member Join Date: Jun 2008 Posts: 310 Rep Power: 18	If it wasn't set for 4cyl mode, then yes. Most after market tachs come from the factory set for a V8. The rotary has the same ignition cycle as a 4cyl, firing twice per revolution.