OK the tiny tachs are mounted together under the main frame attached to a peice of 6061, the wire is wrapped around the spark lead near the spark plug 4 times, the earth wire is between the pull start and the nancelle mounting plate and bolted to the holding the main plate on the nancelle under the washer at the bottom inner side near the pull start hanble, so about 5 inches from the spark lead.
At this point I should state that one works fine and the other is ok up to full rpm then goes off up to 9900.