09-24-2008, 01:39 PM #1
Need help finding direct tach output lead on SHO
I would like to install a digital tach on my SHO, but the inductive type Tiny Tach and PET won't work since the coils are on top of the valve cover and there are no plug wires. I'm assuming the stock tach runs from this wire, but I'm not sure which one it is. Has anyone got access to a wiring diagram that could steer me in the right direction?
Here are the instructions from the tach I'm looking at:
Nordskog Performance ProductsM9004 Mini Tachometer Wiring InstructionsThis tachometer requires a signal from your ignition system to operate. This can either be from the negative terminal on your coil or a direct tach output lead from the distributor or electronic control module. In order to isolate the signal wire from electrical noise interference, we recommend that you use great care to insure that all sensing wires are run as far away from any voltage or signal carrying wires as possible, especially spark plug wires. Before beginning the installation, carefully read through all of the following wiring instructions.
Connect thegreen wire to your ignition signal wire on the negative terminal on your coil or a direct tach output lead on your distributor or electronic control module. Note: If you are using an aftermarket capacitive discharge ignition system such as an MSD, you must use the designated "tach output" connection on the MSD (or other brand) electronic box. You must not make any connections directly to the coil with this type of system. The tachometer is calibrated for use with 8 cylinder engines. If you are using it with a 4 or 6 cylinder engine, you must "recalibrate" the tach for your specific application by cutting the correct "loop" of wire coming from the back of the gauge;
For 4 cylinder operation, cut the blue wire loop
For 6 cylinder operation, cut the orange wire loop
Connect the black wire to a good engine ground (chassis or wire wall grounds can often be inadequate).
Connect the red wire to a 12 volt source which is adequately fused and turns on and off with the ignition switch.
09-24-2008, 05:51 PM #2
Got my answer. Big thanks to Bruce. I think it's awesome to have guys like him on the leading edge of the industry take part in our forum. I just ordered my tach and I'll post some pics after I finish the install.
09-24-2008, 06:25 PM #3
Guess that Modders Anonymous meeting didnt work huh?
09-24-2008, 06:34 PM #4
- Join Date
- Apr 2007
- JUST NORTH OF CUBA-- FL,KEYS
09-24-2008, 07:02 PM #5
09-26-2008, 05:14 PM #6
09-26-2008, 05:16 PM #7
09-26-2008, 06:47 PM #8
It's in the front section of the ski. I haven't looked for it yet, but is a two lead wire, black and green/blue that has a white plug on the end of it. Yamaha even supplied the plug, how convenient.
09-26-2008, 07:06 PM #9
10-22-2008, 01:39 PM #10
Got the tach gauge installed and it looks cool but doesn't work properly. The problem is the way Yamaha set up the signal. I get multiple signals per cycle causing the tach to read 3x the actual rpm(@2000 it reads 6000). Bruce told me he uses a Kowa Tools tach that can be calibrated for a 2 cycle engine to scale down the signal. I'll post the info on the Kowa after I have the model#.
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