The instructions say to wind the tach. signal wire around one of the plug leads to pick up the signal. Has anyone tried connecting the original tach. signal wire to the Trailtech? Seems to me that would be easier, but I've no idea if it would work.
I know that's what I did when fitting an Acewell dash to another bike and it worked fine. But, different dash may need different connection.

I used the plug wire inductor method on a few race bikes. Works fine but here are some tips:
Start with 5 turns in malleable single strand copper insulated wire. DO NOT TERMINATE or loop. Should be open ended unless instructed otherwise. If the signal at the tach is erratic reduce by one turn at a time until the tach signal is consistent. If you get it to work all good. ECU driven plug signal can be a problem if it is a multifire sometimes as the electronic tach are very sensitive though they should have a decent front end filter.
Once you get a decent reliable tach signal Sgoo Goo around the turns and it will stay there for ever. If you are really worried about the permanence of it wrap it with plumbers teflon tape first and it will be possible to remove it if necessary. Because the wire is single strand it tends to be a bit brittle, so you need to anchor it, so it can't flex, and take a multistrand from it to your connector.

Thanks Greg

Forgot. Sometimes a 1Mohm resistor inline with the inductor can help.

Yeah the Acewell instructions say the same thing if you have an erratic reading on the tach to add a resistor.
Still keen to know if I can just go direct from the original tach wire. Might try it anyway, see what happens 

I have used the tach wire on my 2005 chassis for my Acewell. Had some stability issues but havn't looked into it yet. It mounted but not sorted. Works then doesn't. Could just be a pinched wire.