JW 0 #1 Posted July 14, 2016 (edited) Mower is 520H and a 1999 I believe.Engine starts fine but after about 30 minutes of use it cuts off and won't start, I let it sit for an hour and it cranks up and runs and later cuts off again. Battery is charging according to guage and all guages work. Cuts off with mower on or off. Help Edited July 14, 2016 by JW No model number Share this post Link to post Share on other sites
953 nut 59,346 #2 Posted July 14, 2016 I have had this problem and it turned out to be the fuel cap vent wasn't working right; new cap, problem solved. Share this post Link to post Share on other sites
cleat 7,177 #3 Posted July 15, 2016 Are you sure it is fuel related ? Could also be a defective ignition module. 1 Share this post Link to post Share on other sites
Bert 760 #4 Posted July 15, 2016 to I agree with Richard and Cleat, could also be the screen in the tank getting trash stuck to it when there's fuel being pulled through. Share this post Link to post Share on other sites
scotty 252 #5 Posted July 15, 2016 I once had a yard machine that did the exact same thing and the fuel line was dry cracked. Replaced all of it and it seemed to cure it. 1 Share this post Link to post Share on other sites
DougC 2,643 #6 Posted July 15, 2016 Make sure the fuel line hose is not in contact with the oil filter. Heat transfer can occur. 1 Share this post Link to post Share on other sites
boomers_influence 106 #7 Posted July 17, 2016 jw it is time to check the ignition module and coil when it stops. i believe that there is a thread at the top of the electrical section on this site. thank you. boomer ( the used onan engine parts guy, also NOS and new ) Share this post Link to post Share on other sites