BESTDOGEVER 218 #1 Posted July 13, 2016 I am planning to change the Onan in my 518h to an 18 hp magnum from a 418A I know I have to change ignition switch. If I do that what other changes will I need to make.? Share this post Link to post Share on other sites
N3PUY 1,031 #2 Posted July 14, 2016 The safety switches will be different. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,394 #3 Posted July 14, 2016 Here is the wiring diagram for the 418-A. Compare the ignition switch wiring to the engine, pto switch and seat switch. It will be different. Garry 2 Share this post Link to post Share on other sites
BESTDOGEVER 218 #4 Posted July 14, 2016 Thanks guys I thought that might be the case. Ernie Share this post Link to post Share on other sites
