Trailtech Install, Part 22

Cruised around the internet forums for clues on how RFVC impaired riders mount the thermometer to their engines. One idea is to place the sensor right where the oil line feeds into the cylinder head. I replaced the Alu washer proximal to the rockerbox cover. I don't think the pressures are great enough through that banjo bolt to cause much blood loss, so hopefully it will be okay. I've got the bolt backed out right now just to illustrate how it goes together here:



Tacho wire was simple enough, just wrap the busy end five times around the spark plug lead, and ground into the nearest convenient earth circuit, which for me was easiest done via that posilock tap up 'ere



One cannot underestimate the utility of having a cache of used inner tubes. 700x35c worked best to insulate my power switch terminals



And here it's all coming together

Installing the Trailtech computer

Pretty cool device, in theory. Polarity agnostic, so you don't have to worry too much about supply/ground issues. Their tech support said you do not even need to have a fuse on the supply side. I wish I understood why but when I touched the power leads to my battery, it all lit up just fine. Not that you absolutely need to have it hooked up to the bike's power circuit given the CR2032 battery that the unit will work with as well (albeit not as much illumination). Simple magnetic sender for front wheel, and all I have to do is wrap another wire around the spark plug lead to get revs...I fabbed up a little alu plate for mounting, included my ignition switch to be tidy:



The trailtech even comes with a thermometer and while I'd be eager to use it, the sensor takes the place of the crush washer for the spark plug. Any Honda RFVC thug will tell you how little elbow room there is in that zone...ah, the naughty parallels I could rattle off but wont...

More Tacho Fail

I give up. Not sure how I could have fried the refurb tacho like this; wish I could have taken a photo of its guts before returning way back when I initially had a problem -- I'm betting those burn scars were always there. Can't imagine that I fried it a second time on install. Much ado about nothing. Guess I should just go looking for a VDO.

From their Tech Support

Hi Adam,

Sorry for all the troubles we are having here. We got the tacho back. It has blown the internal fuse again. Unfortunately it appears to have got some heat into it before it went. I have attached a picture of the board. When we went to replace the fuse the part on the circuit board it solders to came off, form the heat. Unfortunately there is no repair for this. I the picture this is the area in front of the harness plug right side.

As far as the gauge we sent that somebody stole from you mail. Not sure what to do there as cant really blame you for that.

Kind Regards,
Dan

wiring tach part three

OK, well I powered up the tacho using the black ignition switch lead as advised by pop earlier. Worked fine. Then came splicing the sensor wire into the coil. I tried using the green/ground line first but no signal. Perhaps there was a signal but not the kind the tach needed? There are was a voltage setting that I had to use when calibrating the tach and in the manual it says to set it to the "hi" setting when going off the coil, so my guess is that they are expecting the pulse to come from wire to the CDI...and that was what it required! Thanks guys for sending some comments to help this thing along!

I love how the needle changes color:

wiring tach part two

OK, now for the head scratching. I could use some help here! This bike does not come with any facilities for tach output management, so I'm parsing their instructions on how to patch the sensor into my engine coil directly:

If you wish to connect the ignition coil, the SPA tacho is fully protected. It will connect to any coil including magneto's and is not damaged by reverse polarity. Connect black to chassis, and red to the ignition pulse side of the coil. Do not make any kind of connection to the HT leads or the spark plugs, this voltage is highly destructive

So my guess is to splice both the skinny black, and green tach lead with the "eye" terminal directly to the frame ground in the picture below. And my gut says the red should splice into the CDI line right there.



The coil installation schematic is in the lower right of this page from the manual. When I first read this, it sounded like I should patch the red tach lead into the green/ground lead of the coil because it has a (-) insignia at the terminal on the coil...but that just doesn't make any sense to me!



The bike's wiring diagram is fairly simple as far as these things go.

Below is a table of the various connections to the meter's body. The 10 element array is the one I'm concerned with.

Aside from the +/- leads coming from the tach sensor at the coil which we went over at the beginning, there are 3 other leads attaching here that I need to safely incorporate into the bike's harness somehow:

• Ground was easy: I just spliced it into the same ground line used for my front turn signals.
  
• Red "+12 Volts Battery" lead. It has an inline fuse. I had originally spliced it into the red battery line by the ignition switch, but that made no sense because the tach's LCD lit up as soon as I connected it. Perhaps I'm supposed to use something called a "relay" to mitigate this, but I see no mention of doing so with the tach installation instructions.
  
• There is another red lead with a label on it: "lights on" presumably having something to do with...lights.
  

Curiously, I tried connecting the "+12 Volts Battery" line to the brown line in my bike's wiring harness, thinking it the tach could use the same line that my tail light uses (which switches on with my ignition key). THAT seems to work okay in that the tach powers on only when the ignition is turned on, no idea if I'm overloading my circuit insodoing...presumably the tach doesn't draw that much power tho ???

Oh well, thanks for reading through this for me. If you have any ideas I'd love to hear them. I look at the map on the upper right corner of this window tracking the visitors and wonder what you all are up to?

wiring tacho

Well at some point I'm gonna want to wire in this nice tach I have. It will also function as my speedo/odo. For now, lots of brushing up on motorcycle electrical stuff. My wiring harness has seen better days and all the reading I've done indicates I'd be well served to do it all up proper with MIL spec wire and sealed connectors. All, and I mean ALL the connectors had little spider nests and spider poop. But somehow, it ran before I began this epic process, so let's see If I can get it limping along with the dusty old stuff first.

Anyway, let's roll out some diagrams. Here's the bike's wiring I copied from a Clymer Manual:



The SPA tach that I have came with a few directions; I found their manual PDF on line and show the schematics contained therein below. Since my bike had no tach originally, I guess this means I am left to wire the new one into the ignition coil:



This is just a table of the various connections to the meter's body. SPA provides a wiring harness that plugs into the 10 prong port atop; the shiftlights are left as an exercise for the user who wants to dragrace



The tach also comes with a speedo pickup. I'll run the sensor wire for this thing along the hydraulic line for the front disc brake, I think: