Expert: Everett Peacock - 10/24/2008

Question
I have a 50hp Thunderbolt flywheel CD pointless-coil per cylinder-4 cylinder with electric start. The key switch in the MerControl box burned out. It was the type switch that required a push button choke switch on the top of the control box. I want to replace it with the newer type key switch where you push in the key as you crank the motor to activate the choke solenoid. The problem is the old type switches are labeled ABCDEFG and the new switch is labeled MMBASIC. I've got most of it figured out. In the off position the old switch had continuity between E and D, the new has it between M and M so that should be the battery ground and the orange wire that runs up to the switch box, both use C for the choke, A is battery+ on the old and B is battery+ on the new, E on the old and A on the new are accessory. That brings it down to just S and I on the new switch and that's where I'm lost.On the old switch B (yellow wire) is the starter solenoid.  The new switch calls I the ignition circuit and S the solenoid. Here's the Key switches continuity sequence -- the old = position 1 (off) E-D, position 2 (run) A-F (F being nothing more than the power source off the back of the key switch itself to the choke switch C) and position 3 (run-start) A-F-B
On the new it's position 1 (off) M-M, position 2 (run) B-I-A, position 3 (run-start) B-I-S. Common sense tells me to attach the yellow wire that goes to the starter solenoid to S, but what then gets attached to the I-ignition circuit?
The old switch has a total of six wires that connect at the engine harness, only 5 of them come from the key switch,the sixth is a brown wire that goes from the tach connector to the rectifier. The other five are black-battery-,yellow-starter solenoid,red-starter solenoid to battery+ then to rectifier,orange-switch box,gray-choke solenoid. Is it possible that nothing gets wired to the I-ignition circuit on the new switch? I hope you can figure this out because I don't seem to be able too.

Answer
the new switch should have come with instructions ...can't tell you of a particular wire code..there should be a black wire that comes from the battery ground to the switch and another that goes from the switch to the switchbox to kill the engine...I think it is black w yellow stripe..??