question tacho d-180[ch8207], spike

[aeromarmi]

hi i have the Jabiru 3300 single phase and the D-180, I conected one of the 2 alternator cable trough a 1 amp fuse, to the Left input of the tacho (PIN 32, db37), and its looks to be working fine, but, when I put the throttle between 2200 rpms it rise to 4200 (and of course the engine is working around 2250, 2300), and if I continue with the throttle it drops again to the correct value 2350, it just in that gap rise of rpms, i configured 6 ppr
What do you recomend to correct this?

 

[dynonsupport]

Try adding some resistance inline on that wire, similar to how we instruct for the p-lead hookups. Start with 10K.