Recoil is in the engine cover, so when you remove the cover and try to run it, it gets interesting. Even with stainless drive and prop shafts, they seem to suffer water-in-gear case problems more than they should. Check the oil before you buy. Also check the wiring. Mercs of that vintage tended to have wiring insulation failure. It would crack and sometimes fall off, in places. When there is close to a couple of hundred volts flying around, also interesting. They run surprisingly well for a single cylinder engine when they are right.