Aftermarket tacho on an 1127

[Phill106]

Recently tried to fit a cheap Eblag tacho to my tacholess street fighter project. Wired power in as usual, tacho Signal wire to the Ecu tacho signal wire.

The tacho now doesn't show the correct engine speed, on tick over with the choke on (guessing by sound its at around 1500-2000rpm) and the tacho will show <500rpm. 

Tried reving to a guessed 4000ish and while the tacho does move its very slow and inaccurate. 

Anyone had a similar experience? Or know how to fix?

 

Things iv tried:

1, connecting signal wire to number 1 coil negative. Resulted in no tacho response at all.

2, checked its on 4 cylinder mode rather than 6 or 8. 

3, Expletives 

4, it has good power from aftermarket fuse box, a good earth and a good switched live. 

 

 

[Captain Chaos]

checked 2- or 4-stroke mode?

[Phill106]

Should probably mention it's a 89 gsxr

[Phill106]

checked 2- or 4-stroke mode?

it doesn't have anything to switch it from 2 or 4 stroke that I can see. It's pretty basic. 

[canamant]

Assuming it hasn't got some sort of internal fault it is either not picking up enough pulses or has been set wrong.  Your coil gives one spark per revolution so try picking up off both coils,  Or try calling it a twin.  It depends on whether the settings assume it has a wasted spark or not.?

 

[Ben Slabby]

Try it on 8-cyl? 

[vizman]

buy cheap buy twice......you should have 3 wires [at least], earth, power and signal