I purchased this item for my 2009 Honda Shadow Spirit 750. Making the connections as detailed within the instructions gave me erratic tach operation regardless of what I did. I returned the unit for refund. Too bad as this unit would take care of two issues Honda left off the bike, tach and temp. DK tech support did what they could but they are a distributor for the item. I wish it had worked!
Great little tach but need a filter circuit to work properly
This tack uses a servo motor to move the needle which is great but when I installed it on to my 2017 Indian Scout, the needles were jumping everywhere. I set it up of 4C and 2P (4 cycle, 2 piston) mode as per mfg instructions.
I decided to investigate why this tach was having trouble reading the positive pulse from my ignition coil. I've included pictures and diagram of the filter circuit I created to remedied this problem and make the tach work with many positive pulse elctronic ignition bikes like Suzuki, indian and others.
Original problem: The signal feeding the coil came direclty from the ECU which had a DC component of 12v and lots of high frequency noise both positive and negative that not only confused the tach but also cancled each other making the reading nearly impossible for any tach. See picture of oscilloscope reading.
The fix. (Should work for other tachs and digital ignition system also) I tested on my Suzuki bike and it worked. I develop and engineered a passive filter circuit to cut the negative pulse, reduce noise above the RPM range of ~8000 while removing the DC component that was saturating the tach's direct input. The result is a smooth and accurate working tachometer.
I've posted the simple circuit you can build and order parts for here. All parts are standard and can be obtained anywhere.