Briggs And Stratton Wont Turn Over With Spark Plug In . The engine on my riding lawn mower will not turn over without the sparks plugs removed. Set valves correctly (make sure the piston is 1/4 down from tdc on power stroke, the reason it needs to be down 1/4 is to ensure that the compression release isn't interfering with your valve lifter). Briggs and Stratton 550 lawn mower for Sale in Hemet, CA OfferUp from offerup.com If so, don’t forget to check if there are any electrode burn marks from one end of the plug to another as well as an absence of carbon buildup at its tip. I took the plug out and sprayed some pb blaster small engine tune up spray in there and. Third step, check the ignition system with a spark tester.