Digital speedo. Can't get rev counter to work

[Madb]

Hi everyone. Nice to see old skool back. 

Having problem with getting rev counter working on gsxr750wn. Old counter works fine but can't  seem to get a signal to operate the new digital one. Its one of them koso copy from China.  Anyone tried one? Speedo only seems to work when it want too! 

My bike below at Snetterton. 

Any help on rev signal would be good.  Cheers. Lee

Edited June 30, 2016 by Madb
Miss spelt

[Madb]

One off these speedos. Tried asking company what input required but no reply.  Grrrr. 

 

[Danm54]

I've got the same problem on a genuine Koso. Taking the rpm signal off the ecu, doesn't register on the gauge but there's no info saying what signal its looking for.

[Madb]

Tried ecu pick up. Tried +12 and -12 off coils.  Grrr nowt. Seached net but nowt. Grrrrrrrrrrrtr.

[t3rse]

resistor?

[Danm54]

You do have to set the clocks for the amount of cylinders, hi or lo side of coil etc.

 

If you search for a company called digital speedos then there are a few manuals on there with an explanation how the clocks are set up.

[Madb]

I'll do a lookie on that site. Let ya know the out come. Cheers.

[Madb]

Have set the clocks 1 and  2 and 4cyl but still nowt.

[Madb]

1 hour ago, Danm54 said:

You do have to set the clocks for the amount of cylinders, hi or lo side of coil etc.

 

If you search for a company called digital speedos then there are a few manuals on there with an explanation how the clocks are set up.

I've done all of them methods. Maybe I'll  try using a capacitor and resistor.  If not maybe a stack or motec might fix it! 

[Madb]

Cant wrap wire around ht lead as i use coil sticks tho maybe it might work if i wrap it round a stick. Hmmmmm.

[caferacerdan]

i had a chinese dash similar and to get it to work on my old bike (whos make we shall not mention) I had to add some resistors onto the wire to get it to read!

[Madb]

Hi caferacerdan. Can yer remember the values of said resistors? 

[Danm54]

Doing a little reading on this and the resistor that comes up is 2k ohm.

 

Its needed as the ecu puts out a square wave signal and the clocks like sine wave so the resistor smoothes it out.

 

I'll pick one up from Maplin and try it out tomorrow.

[caferacerdan]

2k ohm rings about right. i used what i had and had 2 resistors connected which if my memory serves me right (i have an awful memory especially for a yoof) was around 2.2k ohm

[Danm54]

Picked up some resistors and tried them but rev counter didn't budge. Connected the oscilloscope and couldn't get a clean reading from the ecu.

Gave up and wrapped a wire around number 1 coil and worked straight away.

Its a stick coil and gave it 5 wraps around the top just under the rubber gromit.

[Madb]

Cool. I'll give it a try.

[Madb]

Tried wrapping wire round no 1 coil it works but only if I touch the connection. Seems I am an inductor!  I'll try a few more turns or may less see where it goes.

[Danm54]

Touch what connection? 

[Dezza]

I had a very similar problem recently with a genuine Koso gauge. There is a separate thread on it but to get it working I used the original wire for the tacho (1100efe motor) which tees into the feed to one of the coils from the ignitor box. At first I got nothing but some trial and error got the unit working by going into the menu and changing the unit's settings. The unit offers a choice between negative and positive feed, and a multitude of engine options e.g. 2 stroke twin, four stroke four. By changing the polarity of the feed the unit started working. It didn't work correctly though  when set to 'four stroke four' so I had to play around with it further. I think it started working correctly on the four stroke single setting. I do not know if the koso knock-off jobs come with a manual like the genuine unit but if it does and it's legible it'll make things much easier to get it working right.

[Madb]

The wire wrapped round the coil to the input for the tachograph feed.. when I was holding the the wires before I connect them the tachograph burst into life. 

[Madb]

Still not working. Hmmm. Going to try square wave to sine wave convertor. 

[Madb]

Does anyone know the exact output frequency of the ecu ??

[Danm54]

Scrap what Ive said, took mine for a test ride and the rev counter is all over the place!

Will have to call Specialist Components to see what output Im dealing with.

[Madb]

Yes need to know the frequency output of ecu so one can adjust values. With three 1k resistors and three caps at 10nf dont work either. And maplins dont stock more then two caps at atime!!! Not my local one. Anyways, use the net to order next time. Some nice person decided it were funny to puncture my rear tyre while in shop. Grŕrrŕrrrrr no screw or nail. Looks more like burn hole.

[Madb]

Anyone had any luck yet?  

Mine might be lucky and get the hammer treatment!!!