I was wondering if anyone knew of a good tach I could use on my 2001 Scrambler 400 2x4. Also if anyone has one on there Scrambler I was wondering whats invovled in hooking it up and where you may have mounted it. Has it worked well.

 

I have one on mine. The Tach is a Sun Supertach II which I purchased from Autozone for about $35. There's a black faced one that's the same for about $29. The choice is yours. You will also need to go to radio shack and pick up a pack of red wire splice/coneectors to connect the wires off the tach to the bike(it actually comes with 4 in the package but you actually need 5. You also need to pick up a pack of wire conectors(yellow I believe). I'm not sure what the proper name for these are. It's the type of connection that you use to join 2 wires together with a crimping tool. Both of these together probably won't cost you $3. While your at the shack, also pick up a tube of clear silicone with the long pointed end on it if you want to add some additional element protectio to it.

#1. Remove the front cowling(hood) off of the bike and disconnect the battery cables in the back of the bike.

#2. Take the mount that comes with the tach and put it in a vice and smash the bottom of it till it's flat and not curved anymore(you'll see what I'm talking about when you look at the mount). Do not flatten out the concave part of the mount that the tach actually mounts on to. You need to flatten the bottom of the mounbt because you will be mounting it onto one of the bolts holding the handlebar in place. You will have to take a bolt off of the handlebar mount (one of them on the front side of the bike)and drill out the hole on the bottom of the tach mount big enough to slide the bolt through.

#3. Use the silicone and apply some all around the inside edge of the face of the tach and use a shop towel(or a rag with little grain to it) to force the silicone into the inside edges of the face. Do the same thing to the bottom side of the tach. Now make sure and slide the protective wire covering all the way up and into the tach housing and then slide the rubber grommet all the way up the wires till it is at the inside edge of the tach housing. Then take the wires and slide then through the tach mount and slide the plastis tach housing securing cap onto the wires all the way up to the tach and tighten the tach onto the mount.

#4. Use some more silicone to fill up the area around the wires coming out the back of the tach and let dry. Make SURE and put the switch on the back of the tach to the 4 cyl setting!

#5. Now mounthe tach by bolting it down onto the front side of the handlebar mount.

#6. Sit on the bike in your normal riding position and gently bend the tach towards the front of the bike until you are able to see it the way you want to.

#7. You will need wire cutters/strippers/crimping tool now. Connect the green wire to the Yellow/red wire coming off the rev limmiter switch located right behind the oil tank on the right side using the red splicing connectors that come with the tach.

#8. Connect the black wire to the brown wire coming off of the headlight wires(connect it as far down as you can so it won't be visible when you put the hood back on the bike).

#9. Connect the red wire to the Red/white(should be able to use the one off the ignition switch although I believe any Red/white would work) off the ignition switch.

#10. Take the wire cutters and cut off a 1' section off the white wire and take the 1' piece and cut it in half. Then twist the 2 pieces together and stick the end into the wire splicing connector and crimp it. Then taqke the white wire coming off the tach and put it into the other end of the crimp connector and crimp it together so that you now have 2 white wires, one of each to connect to the green wires coming from each headlight(that way your tach will be illuminated at night no matter whether you have the light on dim or bright)

#11. Here's a bit of advice: Before you snap the red connectors closed, Coonect the battery back and turn the ignition on and use a power probe to check and make sure that you indeed do have the tach properly grounded and to make sure that you have power to it when the ignition is on and no power to it when the ignition is off. I'm sure this is a cake walk for you as you are a electrical engineer as I think I remember. If everything checks out, turn the ignition switch on and the tach needle should jump to 0. Then fire the bike up and see if it works(it should).

Sorry about the long post and I can't be 100% sure that I didn't leave out a detail, but if i did and you have a question, just let us know and I'm sure either i or someone else here will come up with a answer. Best of luck.

 

This was a post to a friend that is a electrical engineer. I didn't mean to imply that you were. Sorry. If you want to see what one looks like mounted, take a look at mine by cliking on "myurl" at the bootm of my reply.

 

Very thorough.

I've checked fairly carefully, and fund that tach to be the best option for the dollar.

I did mount mine to an existing slot in a bracket the lights mount on. As a result the tach sits in between the lights and the sight plane is about perfect.

On your instructions re: connection the illumination wire to both the high and low circuit, its seems like you've now effectively eliminated the high and low function, as both filaments would be on at either switch setting now. If that wasn't desirable you might want to connect the illum wire to the switched 12v circuit.

 

Well I just checked it out and low and behold the high and low still work just fine, but the tach only lights up when the low is on. Guess I made a boo boo. Back to the drawing board. I'll just have to live with it for now or until it nags at me me enough. Oh well, I tried! Maybe you could straighten out this little screwup and tell me where I went wrong Dfischer?

 

I found a Polaris snowmobile tach on ebay for cheap and it works well. But its not all that useful since the CVT does all of the shifting for you. It is if you are changing CVT springs or doing other mods, but for everyday riding it was just more weight and something else to clean mud off of so I ended up removing it until I need it for tuning.

 

You're right about that. I originally got it and installed it prior to installing the HPD clutch kit. I then used it when I started playing around with different primary springs to get the results I wanted. Now it's just another hood ornament. It's more trouble to take off than to leave on now so I just leave it as is. It does come in handy at the quad drags we have around here too though.

 

Bayou:

It sounded to be like your wiring basically connnected the tach illum wire to both the hi and low beam circuit. That would also mean you connected the hi and low beam together, hence both would be on any time either was on.

If its only on with the low then your circuit to the high beam wasn't succesfull, but that's probably a good thing.

If polaris had provided an independent wire for the taillight that would've been the wire to use. Sadly that wire is switched 12V, so the tailight is on anytime the quad is.

It wouldn't think it worth it to fix it. I suppose one could use a 12v DPDT (double pull double throw, and available @ radio shack) relay with the low and hi circuits in as the pull's (1 each, and in parallel!) and the tach ilum setup on the switched 12v and though either of the throw sides of the relay. Thus when either ligh circuit was on it would pull the relay closed and complete the 12v circuit to the illum. Since the dpdt looks like to independent circuits on the pull side the lights wouldn't be connected to each other. Better, since either pull circuit closes both throw circuits, you only have to connect the illum circuit up once.

Personally, I just said screw it and attached the light to the switched 12v and left it. Hope it helps.

Oh yeah. on the connection, cut the wires on the tach side pretty short and then connect the small round bullet quick connects to each. They're so small they pass throught the sun plastic connect nut. Then you can quick connect and dis-c in a few seconds. I keep mine on only for clutch tuning....

dan

 

I thought of setting it up for quick disconnect as you did and I have what I think might work as well as your setup only with a different twist. I'm gonna use part of a boat trailor or radio wiring harness for my quick disconnect off the back of the tach. I also have some aluminum plating that my brother-n-law(nice to have a welder in the family) is going to cut and bend to make a clamp that will use wing nuts to clamp it to the bars and then just permanently mount the tach bracket to it. That way, all I have to do is loosen a few wing nuts and unplug the harness and it's ready to save until I need to do some further tuning.

 

I started with the trailer jack (and even soldered it one side on) before I realized it won't clear the inside's of the plastic screw....

Must be NICE having a welder around.

luck.

dan