I recently purchased an older g38 from a gentleman and I was wondering how to hook up a Great Planes Gas Engine Kill Switch to it? I am new to gas so any help will be appreciated. Also, there is no choke on the carb, is this common on the old g38's?
Red.

I'm not sure how GP's switch works. I have a plain old toggle switch on mine. Here's a tip for ya- The "Zenoah" toggle switches Horizon sells can be had at Autozone for several dollars less. I have two 38s myself. The newer prop hub version has a carb with a choke. The older prop hub version's carb has no choke. I picked up a couple of choke carbs off of fleabay.

Thanks mrbigg, Did you just rig a switch to ground out the black wire on the ignition? Also what other walbro's with a choke will work on my g38?
Red.

You hook the manual switch inline between the ground wire and engine ground. The other internal switch uses a servo to push the switch on and off inside fuse. A very good setup....have a couple myself.