Chinese SS182 digital speedo installation tips
 

I just completed installation of one of these ebay speedos. Here are a few tips for those who might want to put one in an F1:

According the the ebay seller the tach needs a pulse directly from the pulse generator. The wire that feeds the stock tach won't work. You can tap into the pulse signal at the white plastic gizmo under the rear of the fuel tank that holds a bunch of connectors. The red connector on my 90 has a yellow and a yellow/white wire from the pulse generator. The yellow gives a good signal. I stripped a little insulation back and soldered a wire to the yellow wire, then routed the new wire up to the new tach.
EDIT - OK, this is problematic. Setting the tach to 4 cylinders results in it reading twice what it should, i.e., reads 3000 rpm when running at 1500 rpm. I will continue to work this problem.

EDIT 11/1 This has been resolved, the SS182 tach now works properly from the original tach signal wire. No thanks to the ebay seller, I had to figure it out for myself. Post #29 on page 3 explains what I did:
https://cbrforum.com/forum/cbr-600f-...-152756/page3/

The SS182 expects to see switched 12V (called POWER) and constant 12v (called SPARE POWER). The constant 12 pin keeps your clock accurate and also supplies the red perimeter lights that follow the tach needle. For switched 12V you can use the Black/Brown wire that feeds 12V to the original tach, temp gauge, etc. For constant 12V you can tap the red wire on the connector that goes to the ignition switch.

Since the 90 has no fuel gauge I decided to try connecting the temp sensor to it. The temp sensor is supposed to vary through roughly the same range of reistance as a fuel gauge, roughly 10 ohms to 90 ohms. I haven't had a chance to check the calibration but it does seem to be working pretty well.
Update - this actually seems to work great.

Since the temp idiot light was now free I decided to connect the side stand switch to it. Works perfectly.

When you install the speedo sensor, be sure you have the magnets facing the right way. They will only close the switch if it passes by the south pole, at least that's what I read on the interweb. Easiest way to deal with this is swipe the magnet by the sensor, flip it and swipe again, and mark the side that shows a reading on the speedo. I had a heckuva time getting the magnets (I used two) to drop straight into the allen heads. I finally figured out to put the magnet on the end of an allen wrench of the proper size with the marked side aganst the wrench tip, which allowed me to carefully guide it straight into the hex hole.

You need to input tire circumference, number of "cylinders" and number of pulses seen by the speedo sensor. For starters I am using 1900mm for tire circumference. You can just measure the rollout of your front tire to get a good figure. For cylinders, see above. My F1 has a single pulse coil and the tach is indicating twice the actual rpm when set to 4 cylinders. It gets worse rather than better if you try 2 or 1 cylinder. If the tach had an 8 cylinder setting that would probably work. I will be seeking a solution to this. And for the speedo pulse, as I said I used two magnets, so I set it to two.

I bought nine pin mini connectors to match the ones on the SS182, and cut the original connectors off the stock instrument harness and reterminated them into the new connectors. Here's the colors and pin positions I matched up, first is stock, second is the SS182-

oil press: blu/red, brown/red (position 7)
stand switch to water temp idiot light: yellow/black, green/blue (position 8)
water temp to fuel gauge: green/blue, yellow/white (position 9)
neutral switch: light green/red, green/red (position 10)
left turn: orange, orange (position 12)
high beam: blue, blue (position 13)
power ground: green, green (position 15)
right turn: lt. blue, lt. blue (position 16)
tach: yellow tapped from pulse generator, black/yellow (position 17)
EDIT I now use the original tach signal wire rather than tapping the pulse generator wire.
constant battery power: red tapped from ignition switch, purple (or brown on some models) (position 19)
switched 12V: black/brown, black (position 20)

Some of this stuff may be different for later models, so double check your service manual electrical schematic rather than taking all of this as gospel.

Hope this helps clarify some of the glaring omissions in the instructions that come with the SS182.

Here's a short crummy vid to prove that I really did hook this thing up:

Nice write up...pics would make it easier to understand tho.

Once I get the tach signal source figured out I will add some pics. Looks like taking the signal from one of the leads on the input side of the coils might work. Will try that tomorrow.

That's the way I did it on a Trail Tech I did a few years ago on my ATV.

The tach on this thing is proving to be a challenge. Went to the office and grabbed my scope to try to figure out what is going on. At idle the signal at the pulse generator wire that feeds the ECU is about a 250h-300hz sine wave that measures about 400mv rms, with a "space" about every ten waves. I guess the tach seems to think that each bundle of sine waves is about a 50Hz pulse. The tach works but reads twice the actual rpm when set to the four cylinder setting, and lags quite a bit when you roll off the throttle. So I see 2400 rpm at 1200 rpm idle, etc. If there was an 8 cylinder setting on the tach this would probably work.

The stock tach signal comes from the input of one of the coil packs and thus from a different wire out of the ECU. I can see a very solid square wave of around 5v there, but it's inverted. I think the frequency was about 25hz at idle, need to recheck. The tach is not finding this.

I tried a couple of ideas using capacitors and resistors to see if I could get the tach to work right, but no joy. I do recall something about being asked if the pulse was taken from the positive or the negative side of the coil by the seller (this was over a year ago, memory is foggy on the details). So I think the next thing to try is to make an inverter to flip the pulse at the original tach signal wire to positive. Should be able to do it with a transistor and some resistors, so I'll see if I can cobble together something at work tomorrow.

what happens with the other settings...1and 2 cylinders.

I remember reading somewhere, that due to the wasted spark design, someone got a knockoff to work by setting it to two cylinders. I can't for the life of me find it now though.

Yeah I read the same thing. Must have been a different bike or the signal was being taken from a different location as in this case the rpm readout just keeps multiplying by two as you go to a lower cylinder number. Right now I see 2400rpm at an actual 1200 rpm on the 4cyl setting, then 4800 when switching to 2 cyl, 9600 on 1 cyl.

Thus it would seem that I either need to get the seemingly correct frequency pulse from the stock tach signal line off the coil pack primary to work - possibly by inverting it - or use a frequency divider on the two-times-too-fast pulse generator output. That's a little bit more complex to do, and thus frequency division is plan B after I first try to invert the stock tach signal. Hopefully I will have more to report by this evening. I want to get this sorted while I wait for the carb boots I need to get the bike to run right. The process of sorting this has been a bit challenging because the bike is varying rpm all over the place due to an apparent vacuum leak at the carb boots, but I was able to get it to run well enough to veriify my measurements.

looks great i hope you get it to work!