Wiring new engine into rider, now with two switches?

Hi,
I purchased a used rider that came with a lightly used replacement engine (Kohler CH18). This new engine has a ignition switch that is integral to it. Does anyone know of a wiring diagram, or have advice , on how to wire it so I can still use the existing switch on the dash panel and the remote solenoid, and not the one on the engine?
Thank you.

The CH18 came in several different versions as far as what's on eng & you'll have to determine what your eng has on it as you may have to download one/more service/repair manual(s) from kohler website.In section 8 of manual it will show ign sw connections & wire colors of eng leads in addition you will need wiring diag of mower to figure out how to connect eng wires to existing ign sw as this MAY NOT be a simple one/two wire connection after bypassing sw on eng.

Some CH18 had fixed ign timing,others had a SAM module(automatic spark advance)that you have to provide 12V to in addition to fuel sol on carb with either ign system.Other eng had EFI(electronic fuel injection)along with fixed/auto spark ign in which case you'll need a different manual for eng/wiring connections.

Unless you have STRONG electrical knowledge I would RECOMMEND you leave eng as is as one/two wrong connections can burn out expensive elect parts or possibly damage eng as this is usually a one shot proposition & you don't get a second chance at it.

Thanks,
Not doing anything not an option if I want to get running. Don't have resources for another engine. I have the cover off and all the wiring exposed. I also have made my own diagram of the existing wiring. Also I have downloaded the manual for this engine. The carb Fuel sol gets power from both the start and run switch positions with diodes on each. What if I simply take the existing wiring and extend to take the switch on the engine and extend to the dash? Not using the solenoid?
Thanks for the help.

The sol on carb must be connected otherwise you'll get no gas into main jet of carb OR depending on construction of sol you may be able to remove plunger from sol body & leave sol disconnected,you'll have to check this out.

The next biggest problem is figureing out how existing ign sw works,if your eng has the cd ign(fixed timing)you must have an ign sw designed for magneto/solid state ign(grounding type sw in off/stop position)and I haven't got a clue to what type of ign orig eng had,if orig eng had battery ign & you connect to ign terminal on sw you'll burn out one/both ign modules the first time you turn on sw.You'll also have to check to see if you have a terminal on sw that provides +12v when in run position,you'll need this terminal on sw IF you can't disable fuel sol or plan to use it without trying to disable sol.

Once you determine you have the correct type ign sw(grounding type) on mower for eng ign & you have terminal(s) on sw to provide 12v in run position it's straight forward from there.

Battery feed goes to B terminal on sw,ign kill lead connects to I/M terminal or whatever terminal is grounded to ign sw shell/chassis when ign sw in off/stop position,lead to starter sol on S terminal,if you decide to connect fuel sol one diode lead can connect to S terminal on ign sw OR coil terminal on starter sol,which ever is easier to connect to,other diode lead connects to terminal on ign sw that you have 12v on when sw in on/run position,alt output can also connect to this terminal OR to battery terminal on starter sol.

Sounds like you backed yourself into a corner with this mower.

Thank you for the info

I had thought about that as an option, but you would need to figure out how to include the safety switches - in case you sell the tractor down the road somewhere.