I need a good motorcycle electrician?????????????

ninjapower · Derestricted Danger Joined: 30 Jun 2009 Karma :

Hi peeps a big hello to all.

Can anyone help me with a problem. I have a CBR600FM race bike and I have fitted VFR400 tacho & temp gauges. I got the temp gauge to work ok but having problems with the tacho.... it doesn't work.

Most of the wiring has been messed around with so I'm trying to figure it all out making a new loom as such.

The tacho has 3 wires... Live, earth & pulse. I have 12v dc via the ignition which is ok, the earth is good with continuity and lastly taken the wire from the CDI which is yellow and green but rev counter does not function at all.

Here is my question... How do you check the pulse from the CDI wire on a multimeter? Or do you think the tacho is caput?

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

wire the pulse wire to the low tension side of one of the coils.

ninjapower · Derestricted Danger Joined: 30 Jun 2009 Karma :

I did try this but when it was revving lets say to about 9000 rpm the tacho was only showing 2000? I used to have a mini electronic tacho that was wired that way. Do you think the new tacho does not have the right pulses? Or should I try the other side of the coil?

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

mmmm, how many coils does the vfr 400 have? on your CBR its going to be two twin output coils, with wasted spark, that gives the right amount of impetus to the tacho.

Try the other LT terminal as tachos can be picky.

Ill chase up a VFR400 wiring diagram and have a look to see how its plumbed

ninjapower · Derestricted Danger Joined: 30 Jun 2009 Karma :

Just checked the VFR manual and they also have 2 coils. I will try picking up from another LT coil. Although I had some info on the pulse wire from the CDI. With the bike running it should be outputting 10.5 DC Volts if not that could be the problem. A guy also mentioned that because its a VFR400 tacho the CDI pulse might be configured differently to that of a CBR600. I will try all these ideas tomorrow. Thanks for the help, I will let you know my findings.

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

Mmmm It should work, It seems to have two twin lead coils.......

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

ok, it should be wired to the positive side of the coil.